computer wont log into my wireless network

On the Desktop :

Click on the button type manage wireless into the Search programs and files box and Click the Manage wireless networks or press <Enter>

On the Manage Wireless Connections window . Click on Kevins Network and click Remove then click on Yes to confirm . Then try to connect to Kevins Network and input the password that was shown on the laptop

Does the PC recognize the USB WiFi adapter when you plug it in ?

Ok on the desktop click on the bars icon inside the sys tray on the lower right hand side ( next to the time ) choose your network and input the password .