Use regedit
Under
HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerFileExts
Deleting the sub-key with the same name as the extension and restart.
Use regedit
Under
HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerFileExts
Deleting the sub-key with the same name as the extension and restart.