Networking xp to xp

Heres the deal. I have two computers (desktop and laptop), both running XP Pro. I have them hooked up to a router. Both of the computers can access the Internet fine. Now here's the trouble, the laptop can see the desktop, but the desktop cant see the laptop. I have all the same stuff installed on both network cars (Client for MS Networks, QoS Packet Scheduler, File and Printer Sharing for MS Networks, Internet Protocol (TCP/IP)) and I am sure that they are on the same workgroup. If anyone can provide any assistance I'd appreciate it.
Just installed it from the XP CD, still nothing