Im looking for a program that lets you install other programs into a secondary/virtual registry. any ideas?

i once found a free ware program by googling "freeware". i cant remember what it is, but what it does is let you "test drive" other programs. it does this by installing programs and their settings into a secondary registry. if the program doesnt work out, or messes up your computer, you can restore the other registry. this isnt a typical registry program per se, and not a registry editor, nor is it a SVS layer solution. any ideas what this is? if i remember correctly, its somewhere at a href="http://onlyfreeware.net/" rel="nofollow"http://onlyfreeware.net//a or a href="http://www.onlyfreewares.com/." rel="nofollow"http://www.onlyfreewares.com/./a anyone have any ideas?