Since you were networking fine when both machines were 98, the problem is local to your w2k machine ... no need to worry about cable. No, It doesn't matter if its server or Professional.
If removing NetBeui doesn't solve it (prob. wont).
I checked the stock drivers in 2k and this board and don't find wether your NIC is compatible with 2k... R U sure it is?
If it is...
Check to see that the NIC is enabled (Local Area Connection -> Properties -> Hit the configure button). Also, make sure that an IRQ shows up in the resource tab (9x was famous for detecting a few cards and showing no signs of problems and still not working. If you looked under the resources and entered the missing value for the IRQ, you were up and running - Although I haven't seen 2k do this YET).
I haven't had any problems with AutoNeg. on the Connection Type (Advanced Tab) under 2k, but Jabba may have a point - I've seen this cause headaches in 9x.
Check for new drivers for Win2k for that NIC?
Verify your settings (ip, subnet, etc...)