Try Grif's method in http://reviews.cnet.com/5208-6122-0.html?forumID=44&threadID=9613&messageID=111593. If it really are cookies, you have a lot!
Note that details might be different if you work with profiles or different users. They might have their own copy of Temporary Internet Files and cookies folder.
Hope this helps.
When I run my VirusScan, after deleting my Temporary Internet Files, it still scans 1000's of files in the Temporary Internet Files folder. Any ideas how to delete everything in it?