I don't see pc in local network

[marquezzzzz]

Hello, I have a local network of several PCs (PC1, PC2 and Laptop) plus a media player also connected to the network, as they are all in the same Workgroup and in the same IP address range (192.168.4.X).
PC1-192.168.4.20
PC2-192.168.4.21
Laptop-192.168.4.201 DHCP
Media Player-192.168.4.203 DHCP

The problem is that when I try to connect from the media player to PC1, it does not appear in the workgroup, nor from any of the other PCs, but from the others I can connect by IP, but not from the media player.
How can I make PC1 appear in the workgroup, it's as if it had the option to be seen on the network disabled.
Any ideas?

Note that both PC1/PC2 have XP Sp3 and the laptop Windows 7 Home, the media player is an Oki Soundbar 1G.

Regards and thanks

[incrediboy]

how is it in the firewall? have you checked to see if you really don't have access, or have you just seen that it doesn't appear in the windows explorer?

[marquezzzzz]

@incrediboy:

how is it on firewall? have you checked to see if it really doesn't have access, or have you just seen that it doesn't show up in the windows explorer?

I have the windows firewall disabled.

[incrediboy]

@incrediboy:

has checked to see if you really don't have access, or have you just seen that it doesn't show up in the windows explorer?

[marquezzzzz]

What do you mean if it doesn't have access? By IP you can see all the computers the problem is that from the multimedia it doesn't let me search by IP, I think it searches by NetBIOS name and that's when one of my machines (PC1) doesn't appear.
If I could tell the multimedia computer to search for smb:\\ip\\shared_resource there would be no problem but it doesn't let me, that's why I want the computer to appear in network locations and workgroup.

Regards