Seriously, everyone should clear their cookies every few months. To get rid of all of them, go into your "Windows" directory (on the C drive) and find the "Cookies" folder. It may be hidden - you'll have select the show hidden files option. Open that folder, go to Edit, "select all" and delete them. Don't worry, anything in that folder that really shouldn't be deleted, the computer will tell you.
If you don't want to delete them all, just get rid of the ones you don't want individually.