Windows 7 not seeing XP computer on WORKGROUP

Ok so I have 3 computers at home using three different versions of Windows:

Desktop - XP

• This computer is connected to the internet through a cable modem. The cable modem has a NETGEAR wireless router in tandem.
• This computer can see Laptop #1 and Laptop #2 in the WORKGROUP.

Laptop #1 -Vista

• This computer uses it's wireless card to attach to the network.
• This computer can see Desktop and Laptop #2 in the WORKGROUP.

Laptop #2 - Windows 7

• This computer uses it's wireless card to attach to the network.
• This computer can see Laptop #2 but CANNOT see Desktop (running XP).

All computers are in the WORKGROUP. I have Windows Firewall on all three. For the life of me I cannot seem to figure out why Windows 7 is not seeing the XP computer. Win7 has been set to network discovery and Public Folder sharing (explaining why the other two computers can see it).

Any ideas?
Thank you.

try this on your W7 computer, it worked for me on all our W7 computers:

You cannot view other workgroup computers on the network on a Windows XP-based computer

this is the solution, that worked for me
i really don't know, how it could happen, that the registry code was set that way

Go through this tutorial about sharing with XP, click on the XP tab, it should help.
Sharing files and printers with different versions of Windows - Help & How-to - Microsoft Windows

This one is more general but has good info.
Networking home computers running different versions of Windows

It can also help to get around password problems if you use the same username and password on all machines in the LAN.

After going through all of that if you are still having file access problems try doing this registry adjustment on the Win 7 machine with the problem.

Solution is really easy just modify one key in registry:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
create or modify 32-bit DWORD: LocalAccountTokenFilterPolicy
set the value to: 1

. I could'nt see my XP on the W7-pc. Learned that XP and windows7 both need to be "WORKGROUP" (not HOMEGROUP) and Work network. Still no success. BUT when I started the Service "server" on both PCs I can now see both PCs on both PCs :-D