Why are you trying to degrade the system from SP2 to SP1? Vista with SP2 is much better and more secure (includes all the patches and security updates from SP1 up and until SP2) ?
You can also research this error code http://support.microsoft.com/kb/125174
I have a laptop and a desktop with the same problem while trying to download an update for Service Pack 1. Both computers became corrupted and I had to restore the original operating system with the discs that were created by the owners. Both computers previous to the restore process had Service Pack 2 installed. Now when I try to install Service Pack 1 I get an error that says I may not have permission to access the files specified and the error code listed is the number 5. Has anyone else encountered this type of problem. I don't think it is specific to the units I am working on because it happened to two different machines. Thanks for any help I may receive...

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