Windows

Your question is somewhat cryptic but I presume that the XP machine can see the hard drive on the 98 but not the other way around. Well first you did a good job by verifing that it was not a communication problem by pinging, so software wise make sure on the XP machine that file shareing is installed, second make sure the hard drive is shared (under my computer right click the drive and the left click sharing). In XP for a drive to be shared it must have a link in the shared documents folder,otherwise it will not allow the drive to be viewed by others on the network.

Let me see if i get your question right. You can't browse to the machine with winXP using the Win98. But on the other way around You can Browse the machine running win98 using the WinXP. From what i know You cannot browse to a machine using a NTFS partition using the recent partition like FAT32 of Win98. The NTFS partition was created increase the security of existing Operating System. This process also applies to Win2k because it also use NTFS.

Check that XP hard drive is shared, check share permission and check also security on that drive. NTFS allows you to enable or disable sharing at user level, so you have to allow shares for the user loggen on the Win98 PC. Also you have to set permission for that user.

Go to the XP Computer, right click "My Computer", left click "Manage". Go to Local Users and Groups section, right click the "Users" folder and add a new user for each workstation. The user name and password need to match exactly with those that are being used to log on to the network from the Windows 98 computers. If your shares are set up properly and you don't have a firewall blocking access (Windows XP default firewall settings will kill your network!), you should be able to browse the network. Also make sure all the computers are using the same IP scheme and on the same subnet. Each computer requires a uniqe IP address, assuming TCP/IP is being used. I hope this helps. Good luck!

First you need to make sure that your TCP/IP is setup to have NETBIOS.
Second make sure you have shares setup on Windows XP. Are you using XP Home or XP Pro?
In Win9x you only have 1 set of security setting (for the share itself). On XP you havethose AND a set for the drive (assuming an NTFS partition is in use). You need to make sure the username from the 98 system has permission with the correct password (if you are not using accounts you can allow everyone, but that is NOT advised).
There are other security settings in XP that can affect connectivity, but they are less likely to be an issue in this case.