Best use for an old 250 GB internal hard drive

Hello,

I have a 250 GB hard drive in a USB enclosure. It's from a laptop that I actually sold. I use it to back up another Win 7 laptop, plus a system image. However, I'm not using that laptop either for the last 6 months.

I'd like to use it for a smaller 12" laptop that I'm currently using, that actually has Win XP, as an external drive.

How should I format it? When I connect it to my Win 7 laptop it shows as drives E, G, H, I. ie. it still has the recovery and system partitions from the original laptop that I sold.

Thank you!

When I want to "reuse" a HD I use Diskpart clean.
Make sure there is no data on the HD that you might need, everything should be backed up or copied to some other drive.
Here is a tutorial by Brink:
Disk - Clean and Clean All with Diskpart Command

Thanks David.

What's the advantage of that over the traditional "format" command?

Also I assume that I should do it on my Win XP machine since I'll use it primarily with that?

The diskpart clean will remove the old "Boot code" that could cause problems.
A format does not remove the old boot code, and having old boot code might cause problems going forward.
If you know there is nothing on the HD that needs to be kept, it's best to clean everything, including boot code.
If you're really paranoid and want to make sure there is nothing left on the HD, use the Clean All command.
That will take a LOT longer.
I use a Clean command for a disk I reuse.
IF I wanted to give someone else one of my old HD's, I would do a Clean All.