1. Right-click on the 'Start' button from your desktop and click the 'Explore' option from the shortcut menu.
2. Click the 'OK' button that appears for the 'Class Not Registered' error to close out of the dialog box.

3. Click the 'Start' button from the desktop and then click the 'Run' button. If you don't see the 'Run' button, type 'Run' in the search field and press 'Enter.'
4. Enter 'regsvr32 ExplorerFrame.dll' into the 'Open' field. Click the 'OK' button and then try to run Windows Explorer again. Click the 'Start' button from your desktop if you still receive the error and then click the 'All Programs' option.
5. Select the 'Accessories' option and then click the 'System Tools' option. Click the 'System Restore' option.
6. Click the 'Restore my computer to an earlier time' option and then select a restore date for a time before the error occurred. Click the 'Restore' button and your computer will automatically restart.