First I notice you have IE7 which can be uninstalled and you would be left with version 6.
Second you have a lot of programs starting on start up you don't need running. Go to Run and type in msconfig. Turn off (uncheck) QuickTime, Messenger, Roxio, Hijack this, and anything else that is not needed to start. Those progams can be adjusted within the Preferences or Options to not start up. You can still access them using Start, Programs and then whatever you want to use. Having them down in the system tray makes the easily accessible but they are using valuable resources. Also one of them could be causing your problem. Don't forget to do the cleaning.

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Intel 6320
4 gigs ddr2 ram
160 gig sata
evga 8800 gts video card
vista home premium sp1 - 64 bit