Hi,
From what you just said, it sounds like file and print sharing mightn't be enabled on the W98 machine, "C".
To check, you need to...
right-click the network neighbourhood
choose properties
click on File and Print Sharing
make sure the appropriate boxes are ticked in the next dialog box.
If they are already, then...
right-click the network neighbourhood
choose properties
select the access control tab
make sure you've got "share level access control" enabled.
You can choose the other but its for a finer level of control and you need to muck around with usernames and groups and setting permissions. It really isn't worth it in a home network.
If all that's ok then try mapping a drive on "C" without going through the network neighbourhood.
On windowsXP, in windows explorer...
On the tools menu choose Map network drive.
In the folder field type
either...
\\ComputerName\c
or...
\\IPAddress\c
Where ComputerName is the name of your W98 computer or IPAddress is the IP address assigned to the W98 computer. The c is for the C: drive.
You can either leave the check box checked or not - thats up to you. I prefer to map drives as I need them, myself so I dont choose to reconnect at login.
Let me know how you go with those (if you haven't already tried them...)
Cheers,
Tim.