Try to repair you IE, look in uninstall.

You can also run antispy, it can help or antivirus, it can be some kinde of trojan, may be.
If it will not help.

Delete all programs from autostart first, reboot you PC and check out if it works.
Or
You can also use
http://www.snapfiles.com/get/processexplorer.html
To "kill" programs that you dont know and find this that makes problem.
..........
Try other browsers, t. ex. mozilla or opera if them work.