Lol sounds good. Points taken Mat. Realistically though i'm after something simple and passive to protect and lock the computer for maybe a few minutes at a time. If I was after something more solid, to protect it indefinitely then you're right, use truecrypt. But the point was to make something that could be run, on the fly, straight off the USB. You could say I wasn't wanting to protect the data to any great degree, but moreover protect my spot on the computer to stop people from stealing it. Anyway,still working on it, hit a small bump with the crl+alt+del blocking, but at the moment I have it locking up the mouse and keyboard input indefinitely while the usb is removed, which is good. :P Btw that usb linux boot sounds cool, I saw an article about it on portableapps.