I have been using Registry Patrol since 2007 but I have never experienced the problems you are having. Here's the key, I have used every registry program there is and I finally figured out that, you need to very careful about what you let the program take out. After using System Mechanic my computer crashed and I lost everything because of failing to back up.Although making it sound as though a child can use them, these programs need to be used by someone with an amount of computer savvy because they are basically all the same.
My win2K pro OS crashed. I finally got the repair function on the install CD to work after several trys and had to jump some hoops to some of the programs to start working again. But the USB ports stopped working. I got error reports the winmgmt file was missing or corrupt. It was still where it should be but the device manager manager showed a lot of other stuff disabled. I have a double partition and choice of OS on startup and everything works fine in the other one. I recopied the file from another partition and checked the registry ( don't know my way around the registry) and that didn't help. I also noticed there was a new program icon on the desktop that I haven't installed or heard of before, registry patrol. I deleted it (I had to reboot the computer several times before the control panel's add/remove started working). Registry patrol was in my downloads folder and I don't know how it got there, so I deleted that.Its a little strange for my computer to crash the same time this program appears. I lost a days worth of time. Fortunately I have my programs save data in another partition.
After I post this I going to do a format and clean install. Another days worth of work reinstalling programs. If this was on an office computer instead of home I would have been up all night fixing this.
tuthdoc

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic