Restore windows to previous state upon boot

I was wondering if anyone knew how to do this. Basically, at my school their windows machines will bootup the same exact everytime no matter how I edit the files, delete the files, add files, etc. I can do anything I want to the OS, yet if I reboot everything will be exactly the same as the boot before. The reason why I want to do this is for security reasons. Say I get a keylogger on one boot, I restart my computer and everything is back to normal just as before I got it. I realize that browsing options like cookies and stuff will need to be set then saved for boot. Does anyone know how to configure windows like this?

Here is a better illustration:
June 15 - I install windows and setup all the programs I need.
June 16 - I download applications and install them.
June 16 - I reboot the computer and it reverts back to how it was on June 15th.

EDIT:I actually figured it out There is a program called Deep Freeze. Very useful, look into it. This thread shall deem useful.

 

i think you do a system restore point

 

Yea, the computers at my website use the same program its very interesting. The computer tech at our school is a moron and when the Conficker virus came out he updated the deep freeze point so it crashed the entire server and messed with so much. And every time the computers were restarted it restored the Conficker virus and it happened all over again. (Yes, he is truly that stupid)

 

my old school did the same thing, but i forgot the program name sorry, btw i think you have to have a computer acting as a server too.