bumble: as Summertop said, legally no. in fact, technically it's "no" too. you can't just take a windows partition disc, transfer it to a new hardware and expect it to work. you must install it from a CD for it to work. this is true even if the rest of the hardware (excepting the disc you transfer) is 100% identical. the reason is that windows is looking for IDs on stuff on your motherboard, stores and uses the info. you'd run into a lot of problems with MS software if you don't install things "properly".

In fact, technically Microsoft is fully ready to be able to monitor exactly who is using what software, legal or not, but can't impose it for several reasons. one, such monitoring would be illegal in most countries; second, it would give a huge push to use the cometing free Linux OS.