There's probably a dodgy setting but here are some fundamentals to check:
- can you get local access
- are both PCs in the same domain
- are both PCs having IPs 192.168.1.x where x is not 1 and not the same for both
- subnet mask should be 255.255.255.0 for both
- default gateway should be 192.168.1.1 for both
- PC names are valid and not identical
It may help to knock the WEP and other securities off for the time being, until you are sure all PCs can connect to the LAN.
Don't bother with the USB flash thingie or the Wireless Setup Wizard- you can use DHCP and you are, so assigning IPs is fine, and the security should be off so you should have no probs connecting- use the SP2 Wireless Zero Config as it pwns. It also needs to have a USB port on the router which is dead unlikely...
HTH and
