The meat of this question is that I'm looking for a way to either require a password before using a recovery partition or "break" the recovery partition (specifically, Acer eRecovery) in a way that I can later "unbreak" only by booting normally into windows first.

Here's the full details:

I have a set of new Acer Veriton n260g machines in a computer lab. A lot work went into setting up this lab to work well - for example, Office 2007 and other programs needed by the students were installed, all windows updates are applied, and a default desktop is setup. All in all it's several hours work to fully set up one machine.

Unfortunately, I don't currently have the ability to easily image these machines, and even if I did I would want to avoid downtime even while an image is restored. Therefore, I've taken steps to lock them down — namely DeepFreeze and a bios password to prevent booting from anywhere but the frozen hard drive. DeepFreeze is an amazing product — as long as you boot from the frozen hard drive, there is no way to actually make permanent changes to that hard drive. Anything you do is wiped after the machine restarts. It lets me give students the leeway to do what they want on lab computers without worrying about them breaking something.

The problem is that even with the bios locked and set to only boot from the hard drive, these Acers still have a simple way to choose a different boot source: shut them down and put a paper click in a little hole at the top while you turn it on again. This puts them into the "Acer eRecovery" mode. This by itself is no big deal — you can still power cycle with no impact. But if you then click through the menu to reset the machine (we're now past the point of curiosity and on to intent) it will wipe the hard drive and restore it to the original state.

Of course, a few students have already figured this out and reset a couple machines. That's unfortunate, but inevitable. I don't want to destroy the ability to do this entirely (which I could by repartitioning the drives to remove the recovery partition) but I would like a way to require a password first, or "break" the recovery system in a way that I can "unbreak" only if I first un-freeze the hard drive in DeepFreeze.

Any ideas?