http://support.microsoft.com/default.aspx/kb/935796
Despite having killed some PCs, this short list of programs will be good to look at. If you are using any of these programs, please look around for updates.
Release of SP1 is 3 weeks starting from now. Which is just nice the second Tuesday (Microsoft releases patches on the second Tuesday of each month), where computers with Automatic Updates turned on will download and install SP1.