To disable third-party broswer extensions on Windows Vista:
1. Open Internet Explorer.
2. Click Tools, and then click Internet Options.
3. In the Internet Properties window, click the Advanced tab.

Advanced Internet Properties

4. Clear the check box next to Enable third-party browser extensions, and then click OK.

Restore advanced settings

5. Restart your computer. Once the computer restarts, open Internet Explorer. The third-party browser extensions will now be disabled.