I have very little experience with InstallShield, and I've basically been trained to take over a guy's job at work in about 3 days...so forgive me if the answer to this question is common sense to developers.

The installer I'm building is in InstallShield 12, and it's a basic MSI project. So the installer has 2 server-based prqs, and it downloads and installs the first correctly. It downloads the second, and in the middle of installing it, reboots the system. But it only does that on XP, not on Win7. When it reboots, the installer shows that installation as pending, and when the user selects Install, it proceeds to correctly install that second prq, and goes on to install what's included in the actual installer. And for whatever reason, on the Win7, it runs through the entire installer just fine.
Any advice would be greatly appreciated. Just even an idea as to where I should start looking.

Thanks!