Just be careful when deleting cookies though. Some websites use cookie information to remember your username, password or other data. Its up to the individual as to whether they want to clear out that info.

But, what had been suggested (clearing temp internet files, etc) is generally a good way to go. When clearing out the temp internet files, you may also want to delete offline content.

If the problems still persist, you may want to double-check as to whether you have all the latest updates and stuff for Internet Explorer. ^^