Write-protect, lock or freeze a partition (on Windows XP, 7, 8 x86-x64)

Question

I'm looking for a way to deny write permissions specifically to other software (potentially malicious) OR if this isn't feasible, then lock/freeze a partition across XP, 7 and 8 OSs.

The ideal solution I'm looking for would be:

• easily implemented and usable (like using a built-in Windows utility or a small/light driver and have the ability to "undo" without a system restart)

• if it requires a separate program, then it should be open source code or tiny in size.

I AM already aware of tools like GPEdit or RegEdit but those don't fit my requirements because they mostly? block access to users. And diskpart doesn't seem to fit in from what I could find.

Something along the lines of DeepFreeze would be good, if we don't know or can have a realiable way of only denying write access, except the restart part.

I usually find what I need with Google, sometimes I try all sorts of hacks and tricks to accomplish what I've set out to do but this time after I've searched a while on Google and thinking where I could start I've thought that this would be a great place to ask :)