can't repair a dropped connection

I have recently gotten wi-fi internet connection.
My setup is:
Main system XP Pro, 2 Nic's (1 for wi-fi, the other for ICS)
2nd system XP pro
3rd system laptop

all systems working fine, accessing the internet through the main system fine.

But when the main system loses/drops the connection to the wi-fi antenna, I cannot repair it, I have to reboot the main system to get the connection functioning again.

When I first got the wi-fi setup even though I was given a static IP, it would assign it (DHCP), but it would have an expiration of 1 hour. Therefore it would drop the connection and I could only get it back by rebooting.
I have since manually set the IP address, the default gateway and the DNS server addresses. Now my connection remains for days at a time, but when it does lose the connection, I must reboot again.

Any suggestions??

 

Get new firmware or better hardware.
Are you able to make a connection with the LAN NIC disabled?

 

It is a brand new Belkin/Realtek RTL8139 nic card. It uses the latest drivers.
I did try installing other drivers, but that made no difference (they were all older drivers, I just re-installed the newest).
If I disable the local area connection I cannot get any access at all. ..... Isn't that how it should work????