A number of computers we use here are shared among many users. Some computers in conference rooms are really used for just presentations. But invariably someone will play around with the setting of the computer to such an extent that I can't easily get it back to the state I originally put it in and need to do a system restore. This is really a pain since these computers are used all the time and there isn't much time for me to get them back in working order.
So one day I discover Windows Steadystate. It's free from Microsoft and it does exactly what I want, it returns the computer to the same exact state after each reboot. Microsoft's SteadyState site is really very good and you really don't need a "How-To", since it's all on the site. I think the salient points are that you must clean and prepare the system completely before installing steadystate.
You do have to do a little configuration. When you install SteadyState you still need to turn on Disk Protection. It is wise to click through all the tabs just to be sure there aren't any other settings you wish to change.
The software seems to work as advertised. On a reboot it returns the computer to the state it was in when steadystate was installed. By default, SteadyState installs for all users on the system other than the Administrator (usually the installing account). The application actually has a window that reports which users are being monitored. The users that will be listed are the ones that have logged into the computer prior to installation of the software. For this reason, every login that is going to use the system (in my case this is one shared login) should be entered, and actually login (so the profiles are created) BEFORE installing SteadyState.
UPDATE #1 (2011-11-29): When I went replace my conference room machine with a new computer running Windows 7 Professional x64, I found that Steadystate no longer seemed to be supported for windows 7. After a little looking around I found a version 1.0 of steadystate along with instructions on deploying it. There are a few caveats. The first is that you need to completely format your hard drive in order to install this solution. This is not a big deal except that you may not be comfortable doing this. The second, and probably most limiting item, is that you will need either Windows 7 Enterprise or Windows 7 Ultimate media in order to create the disk that will create your SteadyState installation. The author of the article below does state that you can get a 30 day trial of enterprise and use that.
Here is the blog on the technet site about Windows Steadystate version 1.0:
UPDATE #2 (2014-07-16): The original version of SteadyState didn't work on windows OS's beyond Windows XP. Microsoft has updated Steadystate to run on windows 7, the above technet link takes you to the appropriate page for the new SteadyState for Windows 7. I no longer use SteadyState and have migrated to using Faronics' Deepfreeze instead. Deepfreeze has a couple of quirks (at least in the enterprise edition), but overall I am pleased with it.