Please provide this information: http://www.techsupportforum.com/f217/blue-screen-of-death-bsod-posting-instructions-452654.html I understand that you're not having BSOD's, but the reports will contain information that we can use to get started with this problem.

 

 

Nothing stands out here.
I'd try:

Multiple errors with your Norton, please do the following:

Anti-Virus Removal:
Please do the following:
- download a free antivirus for testing purposes: http://www.carrona.org/freeav.html
- uninstall the Norton from your system (you can reinstall it, if so desired, when we're done troubleshooting)
- remove any remnants of Norton using this free tool: http://service1.symantec.com/Support/tsgeninfo.nsf/docid/2005033108162039
- IMMEDIATELY install and update the free antivirus
- check to see if this fixes the BSOD's

Then perform a complete system scan with the new antivirus to ensure that you're not infected. If unable to install the new antivirus, please post back.

There are also multiple issues with the Bonjour service. Please uninstall it from Control Panel...Programs...Uninstall a program. More info on the Bonjour service: http://www.apple.com/support/bonjour/

If that doesn't fix things, then I'd recommend a repair install of Vista: http://www.vistax64.com/tutorials/88236-repair-install-vista.html

If that doesn't work, then I'd suggest backing up your stuff, wiping your hard drive and reinstalling Windows.