Browser lockup

A coworker of mine ran into a strange issue the other day - the browser on her laptop works fine, for the most part. If she tries to do a google/yahoo/etc search, however, the browser will freeze. This occurs using both Firefox and IE, and we’ve done a few basic things such as clearing the cache and temp files, running Spybot and Malwarebytes, and Avast antivirus, all the no avail.

I’m not really certain what could be causing it, nor how to approach the issue. Essentially, it will complete the search (we will see the results page) but then be non-responsive, and all you can do is shut the browser down from the task manager; everything else works fine.

Does anyone have any suggestions on how to approach this?

(I am aware we could format it and start from scratch, but she’d rather live with the issue than do that, so assume that formatting and reinstalling Windows Vista is not an option.)

Disable McAfee Site Advisor.