Looks like NIS is interfering with IE7. Uninstall NIS completely. Use SymNRT Cleanup Utility
http://www.majorgeeks.com/Norton_Removal_Tool_SymNRT_d4749.html
1. If no joy, an addon my be interfering. Disable Addons. Go to Tools > Add-on Manager, and uncheck the addons.
2. Reset IE settings. Go to Tools > Internet Options > Advanced. Click on "Reset" button. Click OK. Close all browsers. Reboot the computer.
3. Check if a program running in the background is interfering with Internet Explorer. Temporarily disable antivirus, firewall, antispyware, ad-blocker, popup blocker, and all Norton programs.
4. Uninstall and reinstall IE7. Make sure you have the latest updates.