Question : Trying to setup a network with two computers

Hi Experts, I'm trying to setup a Network with two computers, they are connected by a D-Link  DI-524 Wireless and Wired Router. The connection to the internet comes into the router and it is distributed normally to both computers. Here is the catch, My computers don't "see" each other, for them all there is is the internet, I can't share files between them. I need help to know what I should do. Preferable is a step-by-step, taking me through the motions needed.

The configuration on both computers are the following network wise:
they are both set to detect the DHCP automatically, IPs and DNS... I have shared a folder in each of them... Evan tried to share a printer but to no avail...

I run windows XP on both of them.

Any light to be shed into this problem will be much appreciated. Thanks in advance to any Expert out there.

Answer : Trying to setup a network with two computers

Control Panel->System, Computer Name tab, give each computer a name and put them in the same workgroup.
I suggest HOME (all upper case).