Using a recovery disk with a new mobo/build... help please =)

In theory, it should work. However always when swapping out hardware without a reinstall there are big chances of incompatibilities such as drivers and stuff. The chances are you will have to re-purchase Vista because you will no longer be able to activate it since you've swapped out almost everything. Vista will just detect it as a new machine and refuse to activate.

There may be a problem that the HP recovery discs will look at the hardware and think "hey, this isn't a HP machine" and just refuse to install. In that case you'll have to find yourself a Vista disc. The only way to find out is try it.

Legally, the EULA doed not allow the transfer of an OEM operationg system to another computer.

Practically, your recovery disks have the device drivers for the old components (Chipset, Video, CPU, etc), not the new ones. The system will not boot, and even if it would, it will not successfully complete the MS authentification process. You need to use an original install disk to to a Repair Install to get those drivers installed.

As for authentification, if you can get a post and boot, MS is pretty good about issuing new keys (over the phone).

Without at leaast an original operating system install disk, you're going to need to part with some cash.

That's pretty much what I thought. Thanks for the info.