Never ever use a registry cleaner as they do not work most of the time and have a chance of damaging critical files in the process because some programs will for some odd reason link themselves to them because of dumb DRM that exists in this day and age and even after removing the game the DRM can still remain and cause majors issues at fixing the computer if these critical files are accidentally damaged or deleted. The only way of fixing these most of the time is completely wiping the computers hard drive and reinstalling windows.