This has come up in a previous post, i know because it solved the same problem for me, but can't find it. Here's my recollection of what was done.
The win98 machine needs to set up as a user, for the 2K machine, with a password (cannot be blank) i suggest using the user name as the password so it doesn't get forgotten!
On 2k machine, log in as administrator.
Right click my computer
Uncross local users and groups
Open Users Folder
Right Click, in the right hand pane
Select New User
Enter User Name (win98 Network Pc Name)and password
Don't think you need to restart - but you might.
Restart Client and you should be presented with a loggin meesage either during start up or when navigating to the 2K shared drive.
When you've done this you'll stay logged in until either machine is restarted.
Hope i've not missed anything!