Blank entries in Boot.ini file

[Guest Timothy Daniels]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

 

"John John" wrote:

> Confusing to say the least. I would have to do some tests to see what is

> really going on with the bootsect.exe tool. Keep in mind that Microsoft is

> famous for changing terminology and for saying one thing one day and seemingly

> the opposite the next day!

 

I agree. I've always shied away from doing things that didn't have

to be done with a computer (or any complicated system), since I believe

in "If it ain't broke now, all your fiddlin' is LIKELY to break it." So,

I would really like to know if, say installing XP after Vista necessitates

restoring Vista's version of the MBR as well as the Vista system partition's

boot sector. If you have the means, John John, a byte-for-byte comparison

of XP's and Vista's MBRs would really be a help. Absent that, just

seeing if they are interchangeable would suffice, I think.

 

*TimDaniels*

[Guest Bill in Co.]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

Timothy Daniels wrote:

> "John John" wrote:

>> Confusing to say the least. I would have to do some tests to see what is

>> really going on with the bootsect.exe tool. Keep in mind that Microsoft

>> is

>> famous for changing terminology and for saying one thing one day and

>> seemingly the opposite the next day!

>

> I agree. I've always shied away from doing things that didn't have

> to be done with a computer (or any complicated system), since I believe

> in "If it ain't broke now, all your fiddlin' is LIKELY to break it." So,

> I would really like to know if, say installing XP after Vista necessitates

> restoring Vista's version of the MBR as well as the Vista system

> partition's

> boot sector. If you have the means, John John, a byte-for-byte comparison

> of XP's and Vista's MBRs would really be a help. Absent that, just

> seeing if they are interchangeable would suffice, I think.

>

> *TimDaniels*

 

With perhaps a short analysis and dissassembly of that - would be nice.

And perhaps, for completeness, the noteworthy differences in the boot

sectors between XP and Vista (again with some dissassembly).

[Guest Jawade]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

But Vista can startup from a XP MBR if the bootindicator is at

the right place. The MBR (IPL) sends him to the PBR and there

is loaded bootmgr.

 

 

 

In article <uRpWXKReIHA.3756@TK2MSFTNGP06.phx.gbl>, Timothy Daniels <NoSpam@SpamMeNot.com> says...

> "jorgen" wrote:

> > Timothy Daniels wrote:

> >

> >> Oh! Just Windows/DOS. OK, so talk about just

> >> Windows/DOS MBRs. Even just for them, the MBRs

> >> are different.

> >

> > As said, the key point is: they all load the boot sector of

> > the active partition.

> >

> > So when you install xp after vista, the key point is to

> > restore the boot sector. If you don't, you can write all

> > the MBRs you want, they won't fix your problem.

>

> No one has said that only the MBR had to be changed

> to "fix your problem". (Please note that it is not I who has

> the problem of the inquiring poster.) The point of differing

> opinion is whether the *MBRs* of various Windows/DOS

> OSes are different. In that respect, you are mostly correct -

> they are *usually* the same. I say "usually" because there

> is some confusion in the online documentation about Vista's

> MBR.

>

> Here at APCmag, the author is clearly of the notion

> that Vista's MBR differs from that of XP

> (http://apcmag.com/5485/dualbooting_vista_and_xp):

>

> "The Windows XP bootloader gets installed to the MBR

> and Vista can no longer boot." [......]

>

> And following the link to

> http://apcmag.com/5485/dualbooting_vista_and_xp#restoring ,

> we have:

>

> "Restoring Vista and dual booting

>

> "Because you can't use the Windows XP bootloader to boot

> Vista, we have to reinstate Vista's bootloader to the MBR

> and configure it to manage both operating systems."

>

>

> This view is seemingly supported by Microsoft's own

> online documentation

> (http://support.microsoft.com/kb/919529/en-us):

>

> "When you install an earlier version of the Windows operating

> system on a Windows Vista-based computer, Setup overwrites

> everything from the MBR, the boot sector, and the boot files.

> Therefore, the earlier version the Windows operating system

> loses forward compatibility with Windows Vista." [.......]

>

> "RESOLUTION

> "To resolve these issues, follow these steps.

>

> "Note You can run the commands in the following procedure

> by using the command prompt. If you run these commands in

> Windows Vista, run them at a command prompt that has

> elevated user rights. To do this, click Start, click Accessories,

> right-click the command-prompt shortcut, and then click

> Run as Administrator.

> 1. Use Bootsect.exe to restore the Windows Vista MBR and

> the boot code that transfers control to the Windows Boot

> Manager program. To do this, type the following command

> at a command prompt: Drive:\boot\Bootsect.exe /NT60 All"

>

>

> But it turns out that "bootsect.exe" just restores the boot sector

> unless the option "/fixmbr" is added. Alone, "bootsect.exe"

> defaults to "bootsect.exe /fixboot". (See the following webpage:

> http://neosmart.net/blog/2007/bootsectexe-modifies-the-bootsector-not-the-mbr/ ).

> The following reason is offered in the article for the disparity:

>

> "The source of all this confusion is that during the Longhorn/Vista

> beta program, quite a number of builds were shipped with a

> version of bootsect.exe (originally dubbed `fixntfs.exe`) that

> modified both the MBR and the bootsector."

>

> So at one time, the MBR of Vista differed from the pre-Vista MBRs,

> but when Vista was finally released, it had the old MBR. This site

> offers a breakdown of the "bootsect.exe" command syntax if you're

> interested:

> http://thevistaforums.com/index.php?autocom=ineo&showarticle=32 .

>

> The usual source of "bootsect.exe" is the recovery section of the

> Vista installation DVD. But if you don't have the Vista installation

> DVD, it turns out you can also get it from the free download of

> VistaBootPro at http://www.vistabootpro.org/ (where the Download

> link is at the bottom of the webpage).

>

> *TimDaniels*

>

>

>

>

 

--

Met vriendelijke groeten, Jawade. Weer veel vernieuwd!

http://jawade.nl/ Met een mirror op http://jawade.fortunecity.com/

Bootmanager (+Vista +Linux), ClrMBR, DiskEdit (+Linux), POP3lezer,

DOS-Filebrowser, Kalender, Webtellers en IP-log, USB-stick tester.

[Guest Jawade]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

In article <#BJRCXaeIHA.4312@TK2MSFTNGP03.phx.gbl>, jorgen <jg@na> says...

> Bill in Co. wrote:

>

> > And perhaps, for completeness, the noteworthy differences in the boot

> > sectors between XP and Vista (again with some dissassembly).

>

> There is without any doubt big difference in the boot sectors. XP's boot

> sector loads ntldr, Vista's loads bootmgr

 

No, then MBR sends him to the PBR, and there it loads ntldr or

bootmgr.

 

--

Met vriendelijke groeten, Jawade. Weer veel vernieuwd!

http://jawade.nl/ Met een mirror op http://jawade.fortunecity.com/

Bootmanager (+Vista +Linux), ClrMBR, DiskEdit (+Linux), POP3lezer,

DOS-Filebrowser, Kalender, Webtellers en IP-log, USB-stick tester.

[Guest jorgen]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

John John wrote:

> The paper will explain in part why a previous

> Microsoft MBR cannot (or might not?) boot Vista.

 

It actually can, and will do.

 

To make a note. When bitlocker is activated, you have a problem if you

change anything in the MBR. But that is another issue

[Guest jorgen]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

Bill in Co. wrote:

> And perhaps, for completeness, the noteworthy differences in the boot

> sectors between XP and Vista (again with some dissassembly).

 

There is without any doubt big difference in the boot sectors. XP's boot

sector loads ntldr, Vista's loads bootmgr

[Guest jorgen]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

Jawade wrote:

> No, then MBR sends him to the PBR, and there it loads ntldr or

> bootmgr.

 

What i said. Boot sector = PBR

[Guest John John]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

jorgen wrote:

> John John wrote:

>

>> The paper will explain in part why a previous Microsoft MBR cannot (or

>> might not?) boot Vista.

>

>

> It actually can, and will do.

 

Not entirely. Rewriting the MBR with the Windows 2000/XP RC's fixmbr

command will not bother Vista (unless BitLocker is enabled) but

rewriting the disk signature with the Windows 98 fdisk /mbr command will

cause a boot failure. In most cases Windows 2000/XP will hardly bat an

eye and boot as if nothing had happened when the signature is rewritten,

Vista on the other hand will not boot if the disk signature is changed.

 

John

[Guest John John]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

Timothy Daniels wrote:

> "John John" wrote:

>

>>Confusing to say the least. I would have to do some tests to see what is

>>really going on with the bootsect.exe tool. Keep in mind that Microsoft is

>>famous for changing terminology and for saying one thing one day and seemingly

>>the opposite the next day!

>

>

> I agree. I've always shied away from doing things that didn't have

> to be done with a computer (or any complicated system), since I believe

> in "If it ain't broke now, all your fiddlin' is LIKELY to break it." So,

> I would really like to know if, say installing XP after Vista necessitates

> restoring Vista's version of the MBR as well as the Vista system partition's

> boot sector. If you have the means, John John, a byte-for-byte comparison

> of XP's and Vista's MBRs would really be a help.

 

I could post the MBR's but it would have to be htlm, it wouldn't post

too well as plain text, the wrapping would make it nearly impossible to

read.

 

Absent that, just

> seeing if they are interchangeable would suffice, I think.

 

As mentioned in the other post with jorgen, rewriting the MBR with

Windows 2000/XP's fixmbr doesn't cause any problems, unless BitLocker is

enabled. Rewritting the MBR with fdisk /mbr causes a boot failure,

Vista does not tolerate a change in the disk signature.

 

John

[Guest John John]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

Bill in Co. wrote:

> Timothy Daniels wrote:

>

>>"John John" wrote:

>>

>>>Confusing to say the least. I would have to do some tests to see what is

>>>really going on with the bootsect.exe tool. Keep in mind that Microsoft

>>>is

>>>famous for changing terminology and for saying one thing one day and

>>>seemingly the opposite the next day!

>>

>> I agree. I've always shied away from doing things that didn't have

>>to be done with a computer (or any complicated system), since I believe

>>in "If it ain't broke now, all your fiddlin' is LIKELY to break it." So,

>>I would really like to know if, say installing XP after Vista necessitates

>>restoring Vista's version of the MBR as well as the Vista system

>>partition's

>>boot sector. If you have the means, John John, a byte-for-byte comparison

>>of XP's and Vista's MBRs would really be a help. Absent that, just

>>seeing if they are interchangeable would suffice, I think.

>>

>>*TimDaniels*

>

>

> With perhaps a short analysis and dissassembly of that - would be nice.

> And perhaps, for completeness, the noteworthy differences in the boot

> sectors between XP and Vista (again with some dissassembly).

 

I could post both the MBR and Boot Sector for both (W2K & Vista) but it

would have to be htlm, it wouldn't post too well as plain text, the

wrapping would make it nearly impossible to read. If you want to see

the code post again, but don't expect me to disassemble the code, that

is a bit beyond my expertise!

 

John

[Guest Timothy Daniels]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

"John John" wrote:

> The MBR *is* different but the articles that you quote are incorrect, or at

> least partially incorrect.

 

Here's something I found in Wikipedia on "Master Boot Record

(http://en.wikipedia.org/wiki/Master_boot_record#Structure_of_a_Master_Boot_Record):

 

"Differences in MBR Code

 

"Even different versions of the MS-DOS FDISK program,

not to mention the partitioning utilities for other types of

operating systems, may write variations of code to the MBR

sector. For example, the bytes of code written by FDISK

under MS-DOS 6.22, Windows 98 and the Recovery Console

of a Windows XP install CD are all different. Yet, no matter

how great a difference exists in the MBR code, such as that

written by an MS-DOS 3.30 install compared to the MBR

produced by Windows XP, they will all load the boot sector

of any OS residing in the "active" primary partition."

 

"The following table shows how the Standard Microsoft MBR

Code (created by MS-DOS 3.30 through Windows 95) would

appear in a disk editor:"

 

<------------- data ------------>

 

"A total of only 219 bytes (the zero-byte at 0DAh is necessary);

139 executable code bytes, plus 80 bytes comprising its English

set of error messages.

 

"In contrast, the MBR code created by a Windows 2000 or XP

install (seen in this next table) has a total of 383 bytes for its

English version:"

 

<------------- data ------------>

 

In short, the MBRs are different, but they do the same thing -

they load the Volume Boot Record (i.e. the "Boot Sector") of

the "active" primary partition. But the question remains about

whether, say WinXP's MBR would be suitable for Vista.

 

*TimDaniels*

[Guest CZ]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

>> rewriting the disk signature with the Windows 98 fdisk /mbr command will

>> cause a boot failure. In most cases Windows 2000/XP will hardly bat an

 

John:

 

What does the disk signature have to do with the MBR?

 

IIRC, the MBR is a sector that contains executable code, the partition

table, and ends with 55 AA.

And, each partition has a "partition boot sector".

 

 

Have you tested booting into Vista via a Win 98 MBR?

 

From a post I made about a year ago:

David:

 

I did some testing to see if Vista does change the MBR.

On a Vista/Win XP dual boot computer, I ran fdisk /mbr from a Win98 SE

bootable floppy.

 

Results:

1) Vista's dual boot menu displayed in normal manner

2) Vista op system had a short prompt re: installing some drivers (could not

find what they they were about)

3) Vista's EventMgr did not have any relevant error messages

4) Vista ran in normal manner

 

5) When I selected "Other op systems" from the Vista dual boot menu, I

received an error message re: "ntldr" was missing, and the usual boot.ini

type of menu did not display

 

6) What I learned: The BCD store had been changed (note the "device

unknown" lines below)

 

Windows Boot Manager

--------------------

identifier {bootmgr}

device unknown

description Windows Boot Manager

locale en-US

inherit {globalsettings}

default {current}

resumeobject {50c73d4d-e6b3-11da-bc73-d30cdb1ce216}

displayorder {ntldr}

{current}

toolsdisplayorder {memdiag}

timeout 30

 

Windows Legacy OS Loader

------------------------

identifier {ntldr}

device unknown

path \ntldr

description Earlier version of Windows

 

Windows Boot Loader

-------------------

identifier {current}

device partition=C:

path \Windows\system32\winload.exe

description Microsoft Windows

locale en-US

inherit {bootloadersettings}

osdevice partition=C:

systemroot \Windows

resumeobject {50c73d4d-e6b3-11da-bc73-d30cdb1ce216}

nx OptIn

 

7) What I did to correct the problem: ran the following two cmds via Vista

Safe Mode boot:

Bcdedit /set {bootmgr} device partition=D:

Bcdedit /set {ntldr} device partition=D:

 

8) Summary:

I now have a computer dual booting Vista and Win XP via a Win98 SE MBR

 

 

 

Also note posts from a thread that Jill of MS and I were in:

Jill wrote :in regard to the MBR changes made by Vista install:

>> Functional MBR changes included: [made by Vista]

- Trusted Computing Group (TCG) compliance [measured boot leveraged by

bitlocker].

- Default to using LBA addressing over CHS [CHS still supported].

- Obtain drive number from BIOS instead of from partition table.

- Enable the A20 gate [workaround for buggy TCG BIOSes]

 

Functional changes to NTFS [vol] bootcode: [made by Vista]

- TCG compliance [measured boot leveraged by bitlocker].

- Only support LBA addressing [no CHS].

- Detect sector size instead of assuming 512 bytes.

- Load BOOTMGR instead of NTLDR. Fallback to NTLDR if BOOTMGR is not

present.

 

I wrote:

x Thanks.

This agrees with my tests, that Vista can boot from disk00 with the previous

MS MBR (DOS thru XP) provided the active partition boot code calls bootmgr

(and not ntldr).

[Guest CZ]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

Re: disk signature and MBR:

 

From: http://en.wikipedia.org/wiki/Master_boot_record

 

"The MBR may be used for one or more of the following:

Holding a disk's primary partition table.[2]

Bootstrapping operating systems, after the computer's BIOS passes execution

to machine code instructions contained within the MBR.

Uniquely identifying individual disk media, with a 32-bit disk signature;

even though it may never be used by the machine the disk is running on"

 

 

Note that I disagree with the second comment in that IMO MBR queries the

partition table for the active partition, then passes control to the boot

loader of that active partition, which then loads the op system. The MBR is

generic, whereas a partition boot loader is op system specific; the MBR

cannot load an op system.

[Guest John John]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

CZ wrote:

>>> rewriting the disk signature with the Windows 98 fdisk /mbr command

>>> will cause a boot failure. In most cases Windows 2000/XP will hardly

>>> bat an

>

>

> John:

>

> What does the disk signature have to do with the MBR?

 

It's stored in the MBR at offsets 1B8h through 1BBh.

 

> IIRC, the MBR is a sector that contains executable code, the partition

> table, and ends with 55 AA.

> And, each partition has a "partition boot sector".

>

>

> Have you tested booting into Vista via a Win 98 MBR?

 

Yes, I tried it with one of the Vista Release Candidates and Vista

failed to boot after the change. Maybe the final Vista release handles

disk signature changes differently?

 

John

[Guest John John]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

CZ wrote:

> Re: disk signature and MBR:

>

> From: http://en.wikipedia.org/wiki/Master_boot_record

>

> "The MBR may be used for one or more of the following:

> Holding a disk's primary partition table.[2]

> Bootstrapping operating systems, after the computer's BIOS passes

> execution to machine code instructions contained within the MBR.

> Uniquely identifying individual disk media, with a 32-bit disk

> signature; even though it may never be used by the machine the disk is

> running on"

>

>

> Note that I disagree with the second comment in that IMO MBR queries the

> partition table for the active partition, then passes control to the

> boot loader of that active partition, which then loads the op system.

> The MBR is generic, whereas a partition boot loader is op system

> specific; the MBR cannot load an op system.

 

It depends, CZ. In the case of GRUB or Lilo it can actually be

installed *in* the MBR, that is why we sometimes tell folks who want to

remove a Linux dual boot and return the boot functions to ntldr to use

fixmbr to "dislodge" GRUB from the MBR. In the case of removing a

Microsoft OS Loader from the boot sector we tell them to use fixboot,

bootsect or if you want to return the boot loader to Windows 9x use the

SYS commmand.

 

John

[Guest CZ]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

OT:

 

John:

 

You appear to be a non-zealous person.

May I ask your opinion re: Linux vs Vista vs Mac OS X?

 

TIA

[Guest jorgen]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

John John wrote:

> rewriting the disk signature with the Windows 98 fdisk /mbr command will

> cause a boot failure. In most cases Windows 2000/XP will hardly bat an

> eye and boot as if nothing had happened when the signature is rewritten,

> Vista on the other hand will not boot if the disk signature is changed.

 

Then you also change more than just the program code. And it fails

because bootmgr stores the signature in its database. Unlike in

ntldr/boot.ini where you use the physical location, bootmgr uses the

disk signature. Vista's boot manager itself still loads just fine, it

just halts when it cannot find the new signature in the database.

 

The hole point was that the MBR only has one job, and the job is the

same whether you run vista or xp

[Guest John John]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

jorgen wrote:

> The hole point was that the MBR only has one job, and the job is the

> same whether you run vista or xp

 

I don't think anyone said any differently. My point was that replacing

the Vista MBR may prevent Vista from booting properly, and it will if

you replace it with the standard W98 MBR and it may if you replace it

with the Windows 2000/XP MBR. For earlier Windows versions it hardly

mattered but replacing the Vista MBR with a different version is not a

recommended practice.

 

John

[Guest John John]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

I think all three are fine operating systems and I wouldn't have any

problems recommending any of these operating systems. It all depends on

what the user's needs are and what he or she does with the computer.

 

John

 

CZ wrote:

> OT:

>

> John:

>

> You appear to be a non-zealous person.

> May I ask your opinion re: Linux vs Vista vs Mac OS X?

>

> TIA

[Guest jorgen]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

John John wrote:

> I don't think anyone said any differently. My point was that replacing

> the Vista MBR may prevent Vista from booting properly, and it will if

> you replace it with the standard W98 MBR and it may if you replace it

> with the Windows 2000/XP MBR. For earlier Windows versions it hardly

> mattered but replacing the Vista MBR with a different version is not a

> recommended practice.

 

 

It won't break because you replace it with a W98 MBR, it breaks because

fdisk does more than it should. It you use another tool that doesn't

wipe the signature, it will work the same

[Guest John John]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

jorgen wrote:

> It won't break because you replace it with a W98 MBR, it breaks because

> fdisk does more than it should. It you use another tool that doesn't

> wipe the signature, it will work the same

 

....unless or until the user decides he wants to enable BitLocker.

 

John

[Guest jorgen]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

John John wrote:

> I don't think anyone said any differently.

 

Actually, the discussion started because Timothy Daniels said otherwise.

The source he referred to stated that the specific boot loader was

installed in the MBR and not the the partition boot sector

[Guest jorgen]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

John John wrote:

> ...unless or until the user decides he wants to enable BitLocker.

 

Unless I've misunderstood the concept, it wont break there either. It

will only break/go into recovery mode if you change the mbr while

bitlocker is active.

[Guest John John]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

jorgen wrote:

> John John wrote:

>

>> ...unless or until the user decides he wants to enable BitLocker.

>

>

> Unless I've misunderstood the concept, it wont break there either. It

> will only break/go into recovery mode if you change the mbr while

> bitlocker is active.

 

Yes, I think that is correct. It will break if you change the MBR

*after* BitLocker is enabled, the MBR hash is only crated and stored in

the TPM's Platform Configuration Register when BitLocker is enabled, so

when BitLocker is enabled it should/will just create the hash with the

existing MBR be it the Vista MBR or another one, I think.

 

John

[Guest CZ]

Re: Vista MBR vs. XP MBR

 

Re: Vista MBR vs. XP MBR

 

CZ wrote:

> OT:

>

> John:

>

> You appear to be a non-zealous person.

> May I ask your opinion re: Linux vs Vista vs Mac OS X?

>

> TIA

 

 

John wrote:

I think all three are fine operating systems and I wouldn't have any

problems recommending any of these operating systems. It all depends on

what the user's needs are and what he or she does with the computer.

 

 

My response:

John:

 

So, you are a non-zealous person. The world needs more users like you.