You didn't say what sort of network you're on, anyhow...
For best performance you should have the fewest protocols possible
installed, usually you only need TCP/IP in modern networks. Additional
protocols can cause network collisions and slow down the network, remove
unneeded protocols.
Look here for other pointers:
http://users.bigpond.net.au/hutch/win2k/win982kptpnet.htm
This fix explained there could be the answer, it was for me on one of my
Windows 2000 in a mixed environment.
# However when using Explorer to access files on the Win2000 PC using
shared folders is slow, then an additional fix is needed. By slow I mean
that it may take Word or Excel 30 seconds to load and share a file,
depending on its size. In an old W98-95 PtP network this may have been
almost instantaneous. This slowdown occurs because Windows 2000 is
checking to see if scheduled tasks are enabled on the Windows 98
computer. To speed up the process, you can delete a registry key.
Open the Registry Editor and expand this branch:-
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\RemoteComputer\NameSpace
Select this key:- (select the whole folder)
{D6277990-4C6A-11CF-8D87-00AA0060F5BF}
John