I downloaded one of those a while ago and when it said "pay me, pay me" I simply closed the prog then ran it again .... it let me do that over and over until I had cleaned the reg.
Haven't used it since - too much hassle, and not sure it would be value for money.
I thought that MS had a free version somewhere, but never managed to track it down.
There was another one, that had the executable JV16.exe, that was really neat. Unfortunately they author (understandably) decided to make it pay-ware rather than share or free and the most recent versions need a contibution. Haven't done that yet either.
Good hunting
ST