can you see the directories on the old drive?
What kind of messages are you getting?
You didn't mention XP Home or Pro - had you made use of file encryption?
Depending on your answers, access to the files can be as simple as taking ownership to pretty much impossible if you used encryption and didn't back up your key.
I owned a Averatec laptop, XP OS. The laptop died after about 2.5 years and I removed the hard drive and put it in an enclosure. Now I cannot access some personal files that I need access to. Is there anything out there to download, preferrably for free, that I can use to unlock these files?