If neither browser is properly working, you might have a spyware infection. I would suggest downloading both
www.MalwareBytes.org and
ComboFix. You will probably have to do so from the working laptop, then bring them to your other computer on a flash drive or CD. Uninstall AVG for now, then Run the ComboFix utility. When it finishes, install, update and do a full scan with MalwareBytes.
If all looks good and browsing works afterwards, you can either go back to AVG 9 or give Microsoft's new Security Essentials a try which seems to be working pretty well.
Good luck.