Understanding the Processing Order for GPSI

I have always wondered how Group Policy Software Installation knows what MSIs to install when. Looking over Experts-Exchange and several forums/blogs, most made it out to be like magic.

Today, I stumbled across this article: http://technet.microsoft.com/en-us/windowsserver/cc817587.aspx

In that article, a question was asked on how to set the processing order for GPSI. Microsoft’s answer was:
“The software installation extension assigns a Globally Unique Identifier (GUID) to each application. Applications are then installed in GUID order without any preference. Microsoft Systems Management Server (SMS) provides server-side and client-side scheduling. For more information, see the SMS 2.0 Web site.”

Knowing this, you can look at “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\AppMgmt” to see the list of installed GPOs and in what order they process.