https://www.google.com/#q=windows+7+wep+connection+problem

I know you would have read some but WEP is woefully insecure but let me share my last connect to WEP. I could not use the usual click on the WiFi and select the Hotspot method.

I had to create the connection, then set the connection to WEP so Windows would not try anything else. I'm not duplicating the web on that here. But sharing that the stock easy method did fail.