Originally Posted by mike.fro Finally... Back on topic, thanks jeff. Like I said, I don't really know what to look for either and couldn't tell you if my computers performance enhanced or not as I was using Vista up until a week ago when I bought my desktop.

Service Pack 3 offers no known/proven performance enhancements at all, and there's no reason to believe so. The only reported performance increases are related to the Microsoft Office packages, but many believe that this is simply a placebo effect, as benchmarks don't show anything significant.

As for what SP3 actually fixes, there's a huge list here:
http://support.microsoft.com/kb/946480

Have fun