Well, there are no specs on their website for that (I downloaded the web-book) therefore it depends upon the OS you're using... Win98 will successfully allow you to use up to 80gig while XP will allow you to use up to 120Gig (though only Seagate makes these, IBM soon if not already). Depending on processor speed (?) you can upgrade (if you haven't already) to WinXP to get the bigger harddrive capability (and NTFS format, instead of FAT32)..
Ahhh! It's 2003 and wait, whats this!? My computer didn't blow up! ... Well damn, there goes my new Athlon @ 333FSB and my inssurance claim... heheheh