Home Networking Problems

I have a wired linksys router with 4 computers. The networking has worked for 6 months. I have Vista on 2 computers and XP on the other 2. Recently, I can't get any of the computers to network. There was a power outage prior to the problems, but no electrical storms. No problems connecting to the internet. The computers on the network cannot network. I get an unable to find the path type error message. Have run the Network Wizard, checked the ip address, checked the computer and network names and made sure the files and printers can be shared. Still nothing. I am afraid to start re-configuring the router for fear of messing up the internet connections. Any thoughts or help would be appreciated.