Internet cafe security issues

I'm looking for an application that will give me the power of windows xp "group policy" but will allow me to give different permissions to different users, or to different groups on a WinXP local machine.

I'm running an internet cafe, and have serious problems restricting users permissions.
The internet cafe software I use (cybercafe pro) doesn't run on a restricted user account (I'll be glad if you can recomend me another software).

I want the users to be unable to download or install any program, and if they manage to get out of the internet cafe software, not to be able to see the "start" button, or the desktop.

Please advice,
Any tip will be truely appereciated

 

My thought is that you should just allow the users to do what ever, but use a program like the one they use at my college to prevent the changes from being permenent, the one we use is called deepfreeze. I don't have a link try googling for it. Or setuping up you machines to reghost the hd to a fresh state everything night.

 

I played with DeepFreeze a little, but guess I didn't figure it out completly because it did save the changes.
Anyway, this doesn't solve my problem since the users install spam software, send loads of spam and get me in big trouble with my isp. each time like that cost me in a couple of weeks of pleeding to be reconnected and promissing it won't happen again yet, it can be part of a solution, thats for sure.
Cheers

 

I just got some idea, maybe if I find where the policy settings are stored in the registry and instead of LOCAL_MACHINE, put them in CURRENT_USER...
The only thing is that I'm not sure I can figure it out myself..

 

By the way, you mentioned reghosting every night.
Is there an automated way to do that?