Trying To Do Something That Goes Against UI Convention Lock A User Into A Database

We have an old computer that is going to be used as a simple signin and out book for volunteers. We want to restrict people on that computer from doing anything else

I have designed the form, and it is nice and evil in that it doesn't allow you to close it (cancel = true in the forms unload event) or even quit access without killing the process manually with the old ctrl-alt-del (or ctrl-shift-esc) it starts on startup and I have disabled the windows key (using XP so I had to add a binary value to the registry manually)

The problem is they can still alt-tab out of there (despite a NoWinKeys registry key that was supposed to stop that), and they can still change the main access window's size and access the start menu.

The network and local profile is such that they can't do a whole lot if they do get past the form, but there should be a way to stop them from leaving... some sort of API that will regain the focus, then I could just check that the application had the focus every second, and pretty much render the computer un-usable

Any ideas?

Thanks in advance

-mwalts