Can you please install and run Xirrus Wi-Fi Inspector
? Let's see if you find out anything.
To run Xirrus Wi-Fi Inspector, double click the Xirrus icon on your Desktop, you may use the Windows 7 snipping tool to crop or Paint by tapping the Print screen key on your keyboard, open up Paint (Click on Start>All Programs>Accessories>Paint) then choose Edit from the Menu and select Paste, then save it and please attach the file on your next post.
What was your old SSID name? What's the new SSID?
Also, try removing all the wireless profiles (SSIDs) stored in your computer, then re-add SSID.