TThrottle V 7.30 is the last XP version.
If you installed a later version, you need to go back to 7.30.
Go to "control panel" and select programs. Find TThrottle and select Uninstall.
Got to C:\Program Files\eFMer\TThrottle and remove all files. You many want to make a copy of the folder first.
Now install V 7.30 http://efmer.com/b/tthrottle_download_release (http://efmer.com/b/tthrottle_download_release)