Do you have a “Internet browsing center”, School or Library computer (Are you sharing a computer with more than one users) and are you having problems with installing unwanted programs, or downloading unwanted files. Are you wasting time to reconfigure the computer again to the old status ? check the following two software. Both works all most the same way, but windows steadystate is having some more facilities.
1. Windows SteadyState Version 2.5
It creates a cache file in which your operating system operates, meaning any harmful changes can be undone by simply emptying the cache. After downloading it's a snap to install - just a few obligatory clicks and the usual EULA mumbo-jubmo and you're set.
This is from the Microsoft itself.
Read more and download it from Microsoft
2. Sandboxie
Think of your PC as a piece of paper. Every program you run writes on the paper. When you run your browser, it writes on the paper about every site you visited. And any malware you come across will usually try to write itself into the paper.
Traditional privacy and anti-malware software try to locate and erase any writings they think you wouldn't want on the paper. Most of the times they get it right. But first the makers of these solutions must teach the solution what to look for on the paper, and also how to erase it safely.
On the other hand, the Sandboxie sandbox works like a transparency layer placed over the paper. Programs write on the transparency layer and to them it looks like the real paper. When you delete the sandbox, it's like removing the transparency layer, the unchanged, real paper is revealed.
Read More and Download from Sanboxie