Win98 Files to XP

A friend finally decided to upgrade his system after 7 yrs. After that amount of time he's got a lot of data on his old box, some of which he'd like to save of course.
After offering to help him I realized my knowledge and abilities are limited, so I thought I'd better ask for help myself.
My first thought is to simply remove the hard drive from the 98 box, which is now unplugged and in his garage, and connect it directly to his new Dell so he can simply copy the files he wants to keep.
The old computer was a semi-custom box so I currently have no idea what hardware it contains and what might be needed to make the connection to the new one. Also can't remember what model, etc. the Dell is but I would think USB would be the easiest form of external connection. If so, would the purchase of an external USB hard drive enclosure be necc?
He has no problems with me working on his cars but I worry about his reaction if I were to open his "brand new computer" for an internal connection/installation of the old drive. Also the age and size (I think 30gb) of the old drive doesn't seem to make it worth an internal installation.
As I've been writing this I realized I should have gathered more info on his hardware specs, sorry. Hopefully someone can give me some advice anyway.
This is my first post here so if I'm in the wrong catagory, or other mistakes, let me know so I can do better next time.
Thanks for any help you can give.

 

No CD burner I'm afraid, but yes the computer is still functional. I'm hoping to "borrow" for salvage after files are removed.

When he I asked him about saving/transfering a few weeks ago, I don't think he'd ever given it much thought. He came up with the idea of e-mailing files to his daughters machine and then back to the new one when it was set up! To me, this seems like about the clumsiest method imaginable, but I guess it would work if you had enough spare time.

I'll tell him to buy a USB enclosure for next weekend, he needs a new printer cable anyway and it's not my credit card.

Thanks

 

You could also use a a USB JumpDrive or memory stick. You can pickup a 1Gig for under $60.
http://www.nanosys1.com/usb-hd-ma2-1024.html