occam

Hi friends, I have a problem with XP Professional SP2. I'm trying to install Visual Studio Net, but am receiving a message that a program allready issued a reboot request and setup has to terminate untill the system is rebooted and then be repeated. But rebooting does'nt help. The message reappears. Does anyone knows where this reboot request could be hidden - a registry key or some startup hook? Thanks in advance occam