Up grading hard drive

I have an old desktop with a WD800bb hard drive that went south, can I upgrade the drive capacity simply by purchasing a larger capacity hard drive and installing it or is there more to it?

  Also is there any easy solution to try to retreive lost data on old drive?

As long as your computer can support more than 80GB Try a 120GB.

As far as the data you can try searching the net for software to recover the data. Or try these data recovery agents.