I installed Vista SP1 in my Samsung Q1 about a week ago and was lucky enough to get everything working from the first moment without any problem. But that's not the case for many users that have reported the installation process to go crazy in a endlessly reboot. Here is a link for 3 possible solutions brought by Microsoft for this issue.
This problem occurs when Windows Update is installing update 937287 for Windows Vista.
For more information about update 937287, click the following article number to view the article in the Microsoft Knowledge Base:
937287 A software update is available for the Windows Vista installation software feature