Sorry guys, I missed these last few posts.
Anthony has summed up the benefits of Returnil, and I'm just sticking my two penneth in as I've been using Returnil for, I think, about a year now.
I've mentioned in another thread that I've installed/tried out, literally hundreds of programs under Returnil, and I've never encountered any sort of problem. I use the Ram method, rather than have everything written and then removed from the hard drive. (Which I believe happens using the other mode).
Returnil is actually a surprisingly small package on the Hard Drive, it's Program Files Folder being being less than 5mb. I never use the Vitual Partition as I save any stuff to my own partition or a USB flash drive.
I have on occassion had up to a half dozen new programs installed at the same time, and upon reboot, all traces were gone just as I expected them to be.
Returnil can also be used in the opposite direction, so to speak.
You can completely uninstall a program, maybe to try a newer version, or for whatever reason, and when you reboot, the program is still there on your hard drive, because it was never removed in the first place.
What's removed is a copy of that program in memory, and the new version installed in the same place.
I think Returnil is probably the most amazing, and useful, program I have ever came across.
Edit: Almost forgot. On one occasion, Avast picked something up before it got onto my pc, and placed it in the Virus Chest. When I rebooted, there was nothing in the Virus Chest. It had been placed in a copy of Avasts Virus Chest in memory.
Pretty neat.