Hi DSTM;
The free version has less options but you still make a good point.
I suggest just using the free version and the Cleaner tab on the top left.
The next one down deals with the registry (Issues). DON'T USE THIS unless you know what you are doing.
You are right that this program can be used wrong. And always backup the registry when dealing with such.
A safer program might be 12ghosts wash LE. LE edition is free but I use the full program.
http://downloads.cnet.co.uk/0,39100207,39181121s,00.htm
In conclusion heed DSTM's warning on this program or any other program that deals with registry cleaning options.
Thanks DSTM for the warning.