this is quite tricky and it accidentially happens during upgrade to win7.
if you upgraded to win7 and you didnt run the compactibility check, ur more likely to encounter this problem. i'd say you roll back your wireless driver or do an update to the system or uninstall then reinstall the wifi driver.
NB: download the driver from the manufacturer website b4 you uninstall.
if this doesnt resolve the problem, then it must b the wireless properties settings.
The thing is, I did run a compatibility check, and I am hardlined to the internet, this problem was occurring before and after I plugged in my wireless adapter, so it seems to me that my problem has nothing to do with the wireless adapter, or the hardline even since the wireless connection is working perfectly fine and if the hardline failed it should switch to the wireless connection, to my knowledge anyway.
So, since the wireless connection is working, the router is working, and the hardline might be working, everything seems to be pointing to my computer screwing up or the router blocking my computer for some reason.
The only other thing I could think of is that the hardline failed, and my wireless adapter happens to not work with Win 7.