If it was a prebuilt then no, its a nontransferable copy of windows, it tends to be tied to the motherboard. Have you checked for combos? You can save a lot that way and should be able to fit windows in. If you go to college you may have access to the MSDN which will let you get a copy for free.
About 99% of the time u can use the old license and the disk that came with the old machine.
You will have to reactivate windows via phone or internet after u install. Only thing is tho on the old computer i probley wouldnt hook it up to the internet or use it ne more. This could result in a Genuine Windows error and screw over both machines.
At work I lost my OEM windows disk i had in my shop, and i have about 40 dell disks. I use the dell disk to install windows XP on machines here and also I have used licenses from other machine that are DOA to put on Frankenstein stuff i put together here from good parts if needed.
Never had a problem.
Hunter is 1% right and 99% wrong. I have seen that happen in the past but its very seldom. I have seen it happen with an Asus laptop once with Vista and some HP machines. I believe that the disk was propreitary to the key , But usually any OEM disk or OEM key from any brand of PC will work fine.
On my GF's rig that i handed down to her it still uses a XP Home key from a Gateway computer that I had about 7 years ago. Plus that copy of windows has seen about 3 other former rigs i have had since then. Never a problem installing or activating it.