Need help with a wired Linksys Router

[Iceman2286]

Here's exactly what happened. I've been trying to get my router to support an airport wireless adapter and an Xbox 360. I have 3 computers that currently connect to the airport adapter just fine, but only when I directly connect that adapter to the modem. Earlier today I was toying around with the router. I manually reset it once because I forgot the password and username. After that... I went to the router home page and attempted a firmware update. I uploaded the file that I got from the Linksys website (yes I'm 100% positive it was for the right router) and eventually it said settings are successfully updated or w/e. I had the option to click a continue tab so I did it, but that's when everything turned to hell. I haven't been able to get the router to work since. Whenever I reset everything and reconnect it all, I just tries to acquire the network address, and eventually says limited or no connectivity. I followed the instructions for the firmware update to the T. When I try to run the set up disc provided by Linksys, it says it can't detect the router and won't go past step 9. The weird thing about it is that after the firmware update my connection was screwed, but then I disabled the wired LAN connection in the device manager, ran a windows network setup, and my connection was miraculously restored for about 10-15 minutes. I had enough time to look at the router home page again and the version next to the firmware wasn't the one that I downloaded, so I'm assuming that the updated was unsuccessful. I have tried to manually reset the router 6 or 7 times now, and nothing is working. The router is a BEFSR41 version 4.3 wired. Anyone have any thoughts or info on how to fix this? I'd greatly appreciate it.