I want to clean my registry so that I may use free trial version of some software again. I have used before, now when i want to install, it shows that the your license is expired for this machine XXXXXX. Therefore could you some one tell me the way how I can fully clean the registry so that I can use this trial version again?

i have downloaded INTERNET DOWNLOAD MANAGER the free trial version then after i have used it for a couple of times it expired then i have made a COMPLETE uninstallation
but i have noticed that the connection speed decreased significantly so how can i repair (restore) the changed registry configuration back to default ??

I am not against paying for software to clean registry keys, but if there is a free trial version I can use it would help me pinpoint which registry keys need to be repaired.Plus I’m strapped for cash and need a site that can give me a find & fix trial version.If that’s possible!