I have a new build PC, and (eventually) managed to get W7 RC 7100 on it last night. I had some problems connecting to my home network (via USB adapter), but eventually it did. I was really impressed with the download speeds I was getting at that point, much faster than my laptop. Anyway, I downloaded a few thing,s AVG, iTunes, etc. and then installed a couple of games. Had to restart the PC as part of the installations, and this time couldn't get onto the network no matter what. I installed the adapter from the disk that came with it. No idea why it won't connect, no problems connecting the laptop from the same place.SystemAsus P6T SEi7 9206Gb Corsair RAMEcelstor 250GB HDD *2GeForce GTX 295Belkin N USB wireless adapter (can't remember exact model name)

Does your action center flag have any errors? If so can you try the hardware troubleshooter?