I think he means just access the data on it. Well, as it was said, you can't install a desktop drive into the laptop but what you can do is get an empty external hard drive case that matches your drive (SATA or IDE, make sure you get the right one) and hook it up to your laptop, or any computer for that matter, via USB cable. XP is a designation of your operating system and doesn't really help in this matter. Like I said, you need to figure out what standard your HDD drive is using, SATA or IDE. The labels on the drive itself should say that. Also, SATA drives are newer so if your drive isn't ancient it's likely a SATA. IDE cables were also really wide, like 5cm wide and flat cables. SATA ones are much thinner.
AT any rate, once you've found out what type your drive is, you can go external case hunting.Such cases tend to be cheap, IDE ones are probably a bit harder to find these days but you could definitely get a second hand one easy if you can't find one in a store. SATA ones should be really easy to find in any computer store.
So, you get something like this:

Then you just pop your drive in, make sure all the connecting cables are in place, and hook it up to your laptop. Cheap and easy.