I regard system virtualization as an essential last line of defense, so have been looking for a virtualization software for this computer.
This is a win 7 64 bit system. It has a UEFI and a GPT formatted HDD, so I was concerned about any virtualizer software's ability to create a virtual space for the virtual system to run on.
Returnil System Safe Free seems to work OK so far, for a couple of weeks now.
Seems to do what it advertises, protect the "real" system from changes.
Although the installation was not as smooth as the old 2008 version was in win xp, no serious problems occurred.
It is free.
A comparison of the available versions is here:
http://www.returnilvirtualsystem.com/products
When you navigate through the download link it looks like you have to use Trialpay but you don't. That green rectangle on the download page sends you to MajorGeeks.
There is a topic it over at Wilders, it mentions the glitches.
http://www.wilderssecurity.com/showthread.php?t=341478