Great for fixing plugin and instability problem.
Resetting
Select “Start” or the start globe, depending on your version of Windows. If you’re using Windows XP, select “Run.” If you’re using Windows Vista or later, use the “Start Search” box for the next step. Type “inetcpl.cpl” and press “Enter.”
Alternately, open an Internet Explorer browsing window and select the “Tools” menu. Open “Internet Options.”
Select the “Advanced” tab from the Internet Options window. At the bottom of the window, press the “Reset” button. Press “Reset” a second time. Wait for Internet Explorer to reset itself to its default settings. Press “Close” to close the Internet Options window after the process is complete.
Close and reopen Internet Explorer to refresh it. You have now effectively reset Internet Explorer to factory defaults. If you needed to reset Internet Explorer due to a problem with an add-in, install one add-in at a time until you discover which add-in is causing the problem. You can reset Internet Explorer as often as necessary to fix problems.
Microsoft’s Fix It
Though most users can manually reset Internet Explorer settings, Microsoft has created a Fix It solution that will automatically do the process for you. Visit Microsoft’s site and select the “Fix it for me” option. Press the “Microsoft Fix It” button to run the above process automatically.