HD Replacement Question

[Ramen]

My father recently had his HD die on him for some reason. I tried to recover the data from his HD but it's toast as far as I can tell. My question is this: can I install a HD that is of lower capacity than his previous and still use the recovery disc HP included with the system? My brother in his wisdom bought a WD 320GB HD as a replacement for our father's Seagate 400GB HD (model # ST3400820AS). I don't want to open the package, try to recover the system, and then tell them they need yet another HD that is 400GB+ and drag this out farther. The 400GB Seagate seems to be hard to find in stores and I've only found it through some shady online retailers. Any advise would be greatly appreciated.

BTW, I don't think the system is under warranty anymore and my father doesn't feel comfortable sending the system to HP (which I don't blame him).

[JLK03F150]

A smaller HD (400GB to 320GB) will be fine since the Restore Disk is just gonna install Windows and the HP junkware.

If he has any files he really wants try using a IDE/SATA to USB adapter and a freeware program called Recuva. I've managed to help out a few friends with that combo.

[Ramen]

I'll have to give that a try. :-) Thanks for the reply.