The abosolute best method is to backup the hard drive somehow and then format and re-install Windows. This will ensure that you don't have driver issues just putting the drive into a new computer.
If you can't do that for some reason then you'll need a bunch of rabbit's feet or other good luck charms and a few prayers and hail mary's and what not. If possible remove all the old hardware drivers that you can before sticking the drive into the new computer and see if it boots without problems. Then go about installing mainboard drivers, video, sound and what not.
GK
Yes, I made it past newbie w00t.