can ping, but nothing more

My dad has a linksys wireless router. 2 of his computers are hard wired to it and his laptop on the 2nd story connects with a wireless card. We're trying to get both his laptop and the 2nd computer networked to the 1st to map a drive. I've been able to get the laptop mapped to pc1, but pc2 doesn't work well. pc1 and pc2 are both running win2k and the laptop, xp pro. I've shared the folder on pc1 and on pc2, I do run>cmd>ping 192.168.1.102 (which is the ip for pc1). It pings it successfully. But if I then go to run>\\192.168.1.102\c$ or the computer name \\computer-3o7v2k, it can't find it. At one point, it did find it and I was successfully able to map the drive. But upon rebooting, it couldn't find it again. I've tried uninstalling and reinstalling tcp/ip, but no luck. Anything else I can try?

 

Verify that the workgroup is the same on all computers.
Second, check firewalls. It may be simplest to disable all firewalls and see if this solves the problem . If so , reconfigure the firewall to allow the home network.