I got everything I needed from the old hard drive. I still can't bring myself to sell it, though. I had a lot of personal information on that laptop. Even deleted stuff isn't really deleted.
Probably too late now, since you already have a replacement machine.
You COULD just buy a replacement of the same make/model and swap your old hard drive into it. Probably anything close would do, though HP and Dell have a few "special" drivers, so you should at least stay within the same manufacturer and model "line".