Bushfiva,
Thanks for that clarification, you are quite right about the OEM point.
I have to disagree about the second point, though! Although what would be possible is to put the hard disk into the new PC, boot off the Windows CD and do an INSTALL \ REPAIR.
However, this can be more of a pain than it's worth, particularly is the CD is an SP (or 2) behind the disk. Unless you slipstream it first.
But it might have merit, particularly if the original disk can be installed as C and the new disk as D in the new PC.
SD