Hi, everyone
My parents have request me to rebuild their computer for them. They had a very old system, so I replaced everything. Since they wanted to keep their original harddrive(because of the info on it), I left it in the computer. After builing the system I tried to install their original Windows XP Home onto the new harddrive. That is when I found that their OS cd was really a recovery CD. I can't get it to initiate a new install or repair on either the new hdd or the original. I am able to boot the system from the original install in safe mode only.

So, Does anybody have any ideas?

I have already spent more on this than I wanted to, I really don't want to get other OS cd if I don't have to.

Bite the bullet and buy the OEM copy of XP SP3 it's only $89.99.

IF you had all the drivers for the new hardware, and IF you knew what you were doing, you could try to boot into safe mode and remove the old drivers, then install all the new drivers. Then you could try to boot into the old drive in standard mode.

However, considering the age of the old drive (how old?) it would be likely to fail even if everything went according to plan. Which I can tell you, with computers something always seems to come up. Rarely do things go according to plan.

Listen to their advice, go ahead and buy a new os. Consider it an investment for the next several years that will more likely give your parents a worry free experience. Or be prepared to provide round the clock administrative assistance. Really, don't chince out here, this is your parents were talking about.
You can leave the old hard drive in there but I would immediately back up all the data to the new drive (which should be much bigger and faster) or continued use of the old drive would increase chances of failure, and loss of their precious data.