The WhyReboot tool is awesome!!  Thank you, dunnpy!!

Try this tool - WhyReboot - it's free.

It will show you what is going on and why the system belives it requires a reboot.

Not exactly the answer for your issue, but should point you in the right direction.

Hope this helps,

Dunnpy

Reopening this thread again...

Has any one found solution? How do I know if system is pending reboot?

IIRC, MSIExec exits with an exit code of 3010 if a reboot is required. I haven't looked but perhaps there's a testable property for the WindowsInstaller.Installer object?

I would imagine GP performs its magic by looking at system messages via API calls.

Just bringing up this again.

Does anyone know how to detect if a Group Policy deployment has a reboot pending?

For example, a workstation has 2 applications assigned to it.  The first application has a reboot trigger, but AD holds the reboots until the end of the deployment and so starts installing the second application.

How can I condition the second application so that it won't start while a reboot is pending?
Does anyone know how the GP installation tracks if a reboot is requested?

(Besides the file copy pending registry key, since a reboot request can be forcibly triggered by Windows Installer.)

Cheers,
Jeff

So in that case I should probably capture the exit code and create my own flag then. At least that way I know I'm going to capture all reboot requests.

Thanks for the quick response AngelD.

I only think there exist two cases when an actual reboot is required; files in-use which PendingFileRenameOperations is there to handle and kernel services to be started or filterdrivers to be unloaded. I don't think there is any way to find out for the latter.