Under the hood, how does MSI install by GPO work?

[Guest Ola J. Presterud]

Hi!

 

When MSI packages are installed to a local computer at startup through GPO,

how does this process exactly work on the local computer? What is

triggering the installation localside?

 

Is there any way to run a script or hook into this operation, to do some

special processing before and after the installation sequence?

 

 

- Ola

[Guest Anthony]

Re: Under the hood, how does MSI install by GPO work?

 

Hi Ola,

There are two main things going on:

- normal GPO processing logic

- Windows installer processing following the instructions passed in the GPO.

These are pretty much variations of the msiexec command line options.

I guess it depends what you want to do. You can include custom actions in

your msi, or create a second package in the same policy with whatever you

want to do, or you can run scripts conditional on whatever you want. I don't

know of any way to hook into Windows Installer directly and change what it

is doing dynamically with an msi. What you are describing sounds like Custom

Actions in the msi.

Hope that helps,

Anthony, http://www.airdesk.co.uk

 

 

 

"Ola J. Presterud .no>" <opresterud@<etternavn> wrote in message

news:1injdk9357myf.1g2ec7vhsmz4x$.dlg@40tude.net...

> Hi!

>

> When MSI packages are installed to a local computer at startup through

> GPO,

> how does this process exactly work on the local computer? What is

> triggering the installation localside?

>

> Is there any way to run a script or hook into this operation, to do some

> special processing before and after the installation sequence?

>

>

> - Ola

[Guest Ola J. Presterud]

Re: Under the hood, how does MSI install by GPO work?

 

On Tue, 16 Oct 2007 16:06:24 +0100, Anthony wrote:

> There are two main things going on:

> - normal GPO processing logic

> - Windows installer processing following the instructions passed in the GPO.

> These are pretty much variations of the msiexec command line options.

> I guess it depends what you want to do. You can include custom actions in

> your msi, or create a second package in the same policy with whatever you

> want to do, or you can run scripts conditional on whatever you want. I don't

> know of any way to hook into Windows Installer directly and change what it

> is doing dynamically with an msi. What you are describing sounds like Custom

> Actions in the msi.

 

Thanks!

 

My case is that we have a security system working on the local computer,

which should disable some features while installations is performed. So

reworking the MSI pacakges is not an option, this is a workstation-side

only issue.

 

For me, what is not clear is the process going on in the local computer. I

guess it is something like the GPO is fetched from the server (like

gpupdate /force), and then some processing starts. When and how are the

installations triggered? The startupscript, is this executed before

installations starts? Might it be possible to check for pending

installations from this script, and performe some actions depending on it,

before installations is started?

 

Some way to hook into the installation process is what I am looking for,

the best would be just before and just after installations are performed.

 

 

- Ola

[Guest Anthony]

Re: Under the hood, how does MSI install by GPO work?

 

Hi Ola,

Here are some links that may help you arrive at a solution:

Policy precedence:

http://www.microsoft.com/technet/prodtechnol/windows2000serv/reskit/distrib/dsec_pol_blsa.mspx?mfr=true

Control of processing:

http://technet2.microsoft.com/windowsserver/en/library/574c970f-bb64-4f19-8b80-fdef55c136c21033.mspx?mfr=true

Extensions and order of processing: http://support.microsoft.com/kb/216357

General discussion: http://grouppolicy.editme.com/ClientSideProcessing

Custom extensions: http://msdn2.microsoft.com/en-us/library/aa375118.aspx

If you want more specific help you probably need to ask in one of the

Platform SDK groups.

However basically I think that if you need more control of software

installation like that you would just use a software distribution tool

instead of GPO.

Anthony, http://www.airdesk.co.uk

 

 

 

"Ola J. Presterud .no>" <opresterud@<etternavn> wrote in message

news:hi0p3ovg6az7.1l7la23n9i8ed.dlg@40tude.net...

> On Tue, 16 Oct 2007 16:06:24 +0100, Anthony wrote:

>

>> There are two main things going on:

>> - normal GPO processing logic

>> - Windows installer processing following the instructions passed in the

>> GPO.

>> These are pretty much variations of the msiexec command line options.

>> I guess it depends what you want to do. You can include custom actions in

>> your msi, or create a second package in the same policy with whatever you

>> want to do, or you can run scripts conditional on whatever you want. I

>> don't

>> know of any way to hook into Windows Installer directly and change what

>> it

>> is doing dynamically with an msi. What you are describing sounds like

>> Custom

>> Actions in the msi.

>

> Thanks!

>

> My case is that we have a security system working on the local computer,

> which should disable some features while installations is performed. So

> reworking the MSI pacakges is not an option, this is a workstation-side

> only issue.

>

> For me, what is not clear is the process going on in the local computer. I

> guess it is something like the GPO is fetched from the server (like

> gpupdate /force), and then some processing starts. When and how are the

> installations triggered? The startupscript, is this executed before

> installations starts? Might it be possible to check for pending

> installations from this script, and performe some actions depending on it,

> before installations is started?

>

> Some way to hook into the installation process is what I am looking for,

> the best would be just before and just after installations are performed.

>

>

> - Ola