You'd be suprised at the type of problems that are hardware-related.

Is there any more information you can give me regarding these problems? I've done the best I can with the limited information I have. Useful information would be the version of any antivirus and firewalls, your ISP, what hardware is in your computer, the full text of any error message (and IE does give longer error messages than that), details of any web filtering programs running on your computer, and anything else that seems relevant.