Unable to browse in newtwork neighborhood

A customer has a 6 PC peer to peer network throught a router. All PC's are running XP. Each CP can browse the intranet and share files. He recently brought a PC from home on a temp basis however, even though he can browse the internet, he can not browse other PC's on the network. The PC has joined the workgroup, netbios over TCP/IP has been enabled, and all PC "s have static IPs. I can ping every PC from the new PC, but I can not ping it.
I have enabled Netbios over tcp/ip on one other PC without any luck.
When he takes the PC home and changes the workgroup back to MSHome he doesn't have problem browseing the other PC's on his network.
There is no conflict with ip's, PC names etc. that I can see.
Any thoughts????
I'm stumped

 

On the computer from home - since changed workgroup when at office (different network) - have you added new network to firewall settings? That can be a whoopsie.

To check just disable firewall.

 

I've disabled the MS and router firewalls. I have compared every setting I can think of with the other PC's and still nothing.

 

Absolutely will not be a router firewall issue. The problem is inside your network. Turn the router firewall back on ASAP.

 

Still think it may be software firewall on home computer.
Did you re-start computer after turning it off and then verify still off?
According to some posts here MS firewall doesn't always play nice.

That problem of can’t be pinged but can ping other computers sure sounds like it.

Only other thing I can think of: IF home computer is wireless and not at home, or vice versa.
Are changing settings in right network? Sounds dumb but did that once n it drove me crazy finding it. I’ll NEVER forget it or live it down – LOL.

Other then that I’m out of ideas.

EDIT: BTW - just thought of it. What's make of router in office? If a WatchGuard SOHO or several others it can change things.