Hmm...
Might be slightly more tricky as XP Pro makes things a bit more complicated than Home.
Firstly, what do you want to share - files from pro to home, vice versa, both, printers?
Second, right-click on the 'My Computer' icon and select properties. Then click on the 'Computer name' tab and look at the workgroup or domain name - are they the same on both?
---------- Post added at 12:12 ---------- Previous post was at 12:09 ----------
Also have a look at
this page, which applies to both home and pro.