Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

[Guest Spin]

Running Windows XP Pro 64-bit edition. I notice that my primary hard drive

is Disk 0. If I add another hard disk to the system, the primary hard drive

becomes Disk 1! And still works!!! I thought the hard and fast rule was

that disk 0 ALWAYS stays disk 0 REGARDLESS of whether or not an additional

hard drive gets installed. The additional drive in my case is a removable

drive which sits inside a drive bay which replaces the CD-ROM. Am I missing

something?

[Guest Tony Sperling]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

 

Well, you are probably right - AND you are probably missing something? If

your original HD (0) is a SATA drive, which would be reasonable to assume,

when you add a drive that is IDE/ATA the BIOS enumerates this one before the

SATA drive. Since SATA is an extensiion of ATA it looks up all IDE

connections first as it used to and any SATA drives are relegated to second

place in this regard. The BIOS is smart enough to keep CD drives separate

and you may somewhere have a setting where you can configure the added HD

separate from the internal one(s), or different connectors to attach your

cables. You should read your Motherboard Manual carefully, if you end up

adding an internal HD later you could have havoc play with your boot order.

 

 

Tony. . .

 

 

 

 

"Spin" <Spin@invalid.com> wrote in message

news:6624ghF2i6bk9U1@mid.individual.net...

> Running Windows XP Pro 64-bit edition. I notice that my primary hard

drive

> is Disk 0. If I add another hard disk to the system, the primary hard

drive

> becomes Disk 1! And still works!!! I thought the hard and fast rule was

> that disk 0 ALWAYS stays disk 0 REGARDLESS of whether or not an additional

> hard drive gets installed. The additional drive in my case is a removable

> drive which sits inside a drive bay which replaces the CD-ROM. Am I

missing

> something?

>

>

>

[Guest VanguardLH]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

 

Spin wrote:

> Running Windows XP Pro 64-bit edition. I notice that my primary hard drive

> is Disk 0. If I add another hard disk to the system, the primary hard drive

> becomes Disk 1! And still works!!! I thought the hard and fast rule was

> that disk 0 ALWAYS stays disk 0 REGARDLESS of whether or not an additional

> hard drive gets installed. The additional drive in my case is a removable

> drive which sits inside a drive bay which replaces the CD-ROM. Am I missing

> something?

 

NT-based versions of Windows do not rely on the physical detect order of

hard drives by the BIOS in a computer. They rely on a signature placed

in the MBR of each hard drive. Then when you move drives around between

different controllers on the motherboard or to daughercard controller

cards the OS can still locate the appropriate partitions on wherever the

drives got moved. However, moving the drives around can screw up the

BIOS bootup sequence since the BIOS only looks for the bootstrap code in

the MBR on the first physically detected hard disk.

 

http://en.wikipedia.org/wiki/Master_boot_record#MBRs_and_disk_identity

 

Hard to know what really happened because you did not describe your

physical hardware configuration before and after adding the new hard

disk.

[Guest Spin]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

 

"Tony Sperling" <tony.sperling@dbREMOVEmail.dk> wrote in message

news:eKZ08AcmIHA.1768@TK2MSFTNGP05.phx.gbl...

> Well, you are probably right - AND you are probably missing something? If

> your original HD (0) is a SATA drive, which would be reasonable to assume,

<snipped>

 

Great answer! The primary drive is SATA and the secondary drive is ATA.

Your explanation rhymes reasonably!

[Guest Spin]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

 

"VanguardLH" <V@nguard.LH> wrote in message

news:SvadnVgpr4dwYmbanZ2dnUVZ_oKhnZ2d@comcast.com...

> NT-based versions of Windows do not rely on the physical detect order of

> hard drives by the BIOS in a computer. They rely on a signature placed

> in the MBR of each hard drive. Then when you move drives around between

 

Thx for your feedback. I will take this knowledge and build upon it.

[Guest John John (MVP)]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? Andstill works!!!

 

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? Andstill works!!!

 

VanguardLH wrote:

> Spin wrote:

>

>

>>Running Windows XP Pro 64-bit edition. I notice that my primary hard drive

>>is Disk 0. If I add another hard disk to the system, the primary hard drive

>>becomes Disk 1! And still works!!! I thought the hard and fast rule was

>>that disk 0 ALWAYS stays disk 0 REGARDLESS of whether or not an additional

>>hard drive gets installed. The additional drive in my case is a removable

>>drive which sits inside a drive bay which replaces the CD-ROM. Am I missing

>>something?

>

>

> NT-based versions of Windows do not rely on the physical detect order of

> hard drives by the BIOS in a computer. They rely on a signature placed

> in the MBR of each hard drive. Then when you move drives around between

> different controllers on the motherboard or to daughercard controller

> cards the OS can still locate the appropriate partitions on wherever the

> drives got moved. However, moving the drives around can screw up the

> BIOS bootup sequence since the BIOS only looks for the bootstrap code in

> the MBR on the first physically detected hard disk.

>

> http://en.wikipedia.org/wiki/Master_boot_record#MBRs_and_disk_identity

>

> Hard to know what really happened because you did not describe your

> physical hardware configuration before and after adding the new hard

> disk.

 

Actually, there is another layer (underneath the signature mechanism)

that creates the Harddisk# directory, this is done by the Disk Class

driver and the I/O manager when NT is in the early booting stage. These

disk objects such as \device\harddisk0 are created before the I/O

Manager calls the IoAssignDriveLetters function which in turn reads the

registry and assigns drive letters to the NT disk Objects created

earlier by the Disk Class Driver. It is not unconceivable that the disk

ordinal number be different in the Disk Manager and that the

partition(s) on the disk still retain their assigned drive letters.

 

John

[Guest Spin]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

 

"Spin" <Spin@invalid.com> wrote in message

news:662p7oF2iklcpU1@mid.individual.net...

> Great answer! The primary drive is SATA and the secondary drive is ATA.

> Your explanation rhymes reasonably!

 

Anyway I can tell the system, to enumerate IDE AFTER SATA (instead of the

default which is IDE first)?

[Guest Bill in Co.]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

 

Spin wrote:

> "Spin" <Spin@invalid.com> wrote in message

> news:662p7oF2iklcpU1@mid.individual.net...

>> Great answer! The primary drive is SATA and the secondary drive is ATA.

>> Your explanation rhymes reasonably!

>

> Anyway I can tell the system, to enumerate IDE AFTER SATA (instead of the

> default which is IDE first)?

 

Unless such an option exists in BIOS (which seems highly unlikely), I doubt

it.

[Guest Tony Sperling]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

 

Like Bill says - any such option will have to sit in the BIOS, but I do not

think it must be 'Highly Unlikely' - I have more than one machine of

different brands running that does this, but it is highly likely that you

should have to be on good friednly terms with your BIOS - you may have an

option to flash to a newer version, or simply do it the hard way and

close-read every single word that appears in every single page inside the

BIOS Setup.

 

You may have an IDE sub-section under the Advanced section, if you enter

this you can see the devices that the machine is currently aware of, and you

can usually arrange them with the '+' / '-' keys. Your controlling keys may

vary according to the language of the keyboard - whatever you have will fit

the english keyboard but the manufacturer usually made provisions for this

so it boots in a keyboard/language transparant way, you may have to

experiment there. It's usually not a problem.

 

Do Not Make Changes That You Don't Understand!

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

 

For a good starting-point, I would go ahead and turn OFF every single

setting in the BIOS that you KNOW that you are not going to need, things

that support devices that are not installed, it's a great exercise and it

will shorten the time it takes the machine to Boot and it may become more

stable or robust.

 

If you don't have your Motherboard Manual, get it! Most manufacturer's have

it for download in the BIOS and Driver Support section. When You have it,

read it and get familiar with it, your digital buddy will thank you for it!

 

If it's a Notebook, you may have 'close-to-nothing' that can be changed in

the BIOS, then you are out of luck, but you may have an option to attach

and/or remove devices before installing the OS, it will usually remember the

state it was in when the OS was originally installed! (Vista has changed

this a bit. . .)

 

Log on to the site that has drivers and BIOS updates for download of your

system - it should have some kind of Forum, register yourself and if it's

any good, get to be a regular and you'll probably have a selection of

knowledgeable people helping you out with any issues that are directed

towards YOUR specific issues.

 

Good Luck!

 

 

Tony. . .

 

 

 

 

 

 

"Bill in Co." <not_really_here@earthlink.net> wrote in message

news:uLQ8bwfmIHA.1164@TK2MSFTNGP02.phx.gbl...

> Spin wrote:

> > "Spin" <Spin@invalid.com> wrote in message

> > news:662p7oF2iklcpU1@mid.individual.net...

> >> Great answer! The primary drive is SATA and the secondary drive is

ATA.

> >> Your explanation rhymes reasonably!

> >

> > Anyway I can tell the system, to enumerate IDE AFTER SATA (instead of

the

> > default which is IDE first)?

>

> Unless such an option exists in BIOS (which seems highly unlikely), I

doubt

> it.

>

>

[Guest Tony Sperling]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

 

Thank you, JohnJohn!

 

I must admit, I was not aware of the actual sequence of what call's what and

then ends up going where? But taking this into account, and on this level,

has a tendency to have things getting messy, as this may look like

conflicting explanations - when they're really overlapping pieces of

mutually supporting explanations (?). The OS internally enumerates devices

differently than the BIOS - often starting from (1), but then you have the

OS software utilities that reads off the BIOS and doesn't make use of the

internal enumeration. In short - if you are not programming, you're likely

to have more help from getting to know the BIOS and make inquiries about

specifics that you don't understand. If you are programming, or an OS

hard-core troubleshooter, of course, you need to know it all! But you are

absolutely right, other things could play tricks with the signatures and

drive-letters!

 

:0o)

 

 

 

Tony. . .

[Guest John John (MVP)]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? Andstill works!!!

 

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? Andstill works!!!

 

You're welcome, Tony.

 

I think the information supports what you have explained in your other

post, the disk object number may change depending on how the information

is obtained from the BIOS or on what other disks are added to the

computer. When ntldr starts the boot process it calls on NTDETECT.COM

to get the hardware information from the BIOS and I think that the disk

object number assigned by the I/O manager and the Disk Class driver is

influenced by the order in which NTDETECT.COM enumerates or presents the

disks to the I/O Manager, or in other words on how the BIOS presented

the information to NTDETECT.COM in the first place.

 

If one were to have only one disk in the computer and by "mistake" place

it on the Secondary IDE controller and install Windows on this disk,

this would show up as \device\harddisk0 in the Object Manager. I'm

almost sure that if you were to later add a disk on the Primary IDE

controller that the new disk would become \device\harddisk0 and that the

one on the Secondary controller would become \device\harddisk1, much as

what you said, re: SATA/IDE. It all depends on how the disks

information is presented to NTDETECT by the BIOS.

 

This change in the disk object number would in no way affect the drive

lettering, the IoAssignDriveLetters function *always* reads the Mount

Manager's database in the registry and *always* respects previously

assigned drive letters, the disk object number is somewhat irrelevant,

the symbolic link for the drive letter is made to the disk that has the

proper signature regardless of the device's object number.

 

John

 

Tony Sperling wrote:

> Thank you, JohnJohn!

>

> I must admit, I was not aware of the actual sequence of what call's what and

> then ends up going where? But taking this into account, and on this level,

> has a tendency to have things getting messy, as this may look like

> conflicting explanations - when they're really overlapping pieces of

> mutually supporting explanations (?). The OS internally enumerates devices

> differently than the BIOS - often starting from (1), but then you have the

> OS software utilities that reads off the BIOS and doesn't make use of the

> internal enumeration. In short - if you are not programming, you're likely

> to have more help from getting to know the BIOS and make inquiries about

> specifics that you don't understand. If you are programming, or an OS

> hard-core troubleshooter, of course, you need to know it all! But you are

> absolutely right, other things could play tricks with the signatures and

> drive-letters!

>

> :0o)

>

>

>

> Tony. . .

>

>

>

[Guest Bill in Co.]

Re: Hard drive is Disk 0 CHANGES to hard drive is Disk 1??? And still works!!!

 

Tony Sperling wrote:

> Like Bill says - any such option will have to sit in the BIOS, but I do

> not

> think it must be 'Highly Unlikely' -

 

I stand corrected by assuming this meant some generic checkbox option for

IDE after SATA, instead of thinking of that ordered list in BIOS!! (well,

duh to me). :-)

> I have more than one machine of

> different brands running that does this, but it is highly likely that you

> should have to be on good friednly terms with your BIOS - you may have an

> option to flash to a newer version, or simply do it the hard way and

> close-read every single word that appears in every single page inside the

> BIOS Setup.

>

> You may have an IDE sub-section under the Advanced section, if you enter

> this you can see the devices that the machine is currently aware of, and

> you

> can usually arrange them with the '+' / '-' keys. Your controlling keys

> may

> vary according to the language of the keyboard - whatever you have will

> fit

> the english keyboard but the manufacturer usually made provisions for this

> so it boots in a keyboard/language transparant way, you may have to

> experiment there. It's usually not a problem.

>

> Do Not Make Changes That You Don't Understand!

> -----------------------------------------------------

>

> For a good starting-point, I would go ahead and turn OFF every single

> setting in the BIOS that you KNOW that you are not going to need, things

> that support devices that are not installed, it's a great exercise and it

> will shorten the time it takes the machine to Boot and it may become more

> stable or robust.

>

> If you don't have your Motherboard Manual, get it! Most manufacturer's

> have

> it for download in the BIOS and Driver Support section. When You have it,

> read it and get familiar with it, your digital buddy will thank you for

> it!

>

> If it's a Notebook, you may have 'close-to-nothing' that can be changed in

> the BIOS, then you are out of luck, but you may have an option to attach

> and/or remove devices before installing the OS, it will usually remember

> the

> state it was in when the OS was originally installed! (Vista has changed

> this a bit. . .)

>

> Log on to the site that has drivers and BIOS updates for download of your

> system - it should have some kind of Forum, register yourself and if it's

> any good, get to be a regular and you'll probably have a selection of

> knowledgeable people helping you out with any issues that are directed

> towards YOUR specific issues.

>

> Good Luck!

>

>

> Tony. . .

>

>

>

>

>

>

> "Bill in Co." <not_really_here@earthlink.net> wrote in message

> news:uLQ8bwfmIHA.1164@TK2MSFTNGP02.phx.gbl...

>> Spin wrote:

>>> "Spin" <Spin@invalid.com> wrote in message

>>> news:662p7oF2iklcpU1@mid.individual.net...

>>>> Great answer! The primary drive is SATA and the secondary drive is

>>>> ATA.

>>>> Your explanation rhymes reasonably!

>>>

>>> Anyway I can tell the system, to enumerate IDE AFTER SATA (instead of

>>> the

>>> default which is IDE first)?

>>

>> Unless such an option exists in BIOS (which seems highly unlikely), I

>> doubt

>> it.