I've had Windows 7 for about 2 months now, and it usually works fine, except now recently my internet randomly goes down and it gives the error message "Unidentified Network- No network access". If I run network diagnostics, then unplug and reset the router, it works again, but a few hours later it will go down again. The error says "Local Area Connection doesn't have a valid IP configuration".
My router is a Linksys WRT54G and I have comcast hi-speed internet.