CentraSite 3.1.8 Installation "Reboot Pending"-Err

Hello together,

I am evaluating different SOA-Governance-Tools. When I trying to install, I get the known “Reboot Pending”-Error from InstallShield.
I rebooted the machine several times.
OS: WinXP Professional SP2
Is there a solution, without changing keys in the registry? (My admin wouldn’t give me the permissions …)

Best Regards