Windows 7 Laptop Limited Connection to Wifi Since New Computer Was Added to the Network

For Christmas, we got a new desktop computer. Since the computer was built and connected to the wifi network (it is not connected with an Ethernet cable), my personal laptop has not worked with the wifi network. I only get "limited access." If I go downstairs closer to router it immediately works, and if I stay in the room where it does work and turn off several devices' wifi (checking if there was too many devices on the network), there's still no luck. When we turn the desktop off, the wifi works on the laptop, and it has worked perfectly for a year in the same exact place. My first resorted to updating the wireless card, so it is not the problem. No other devices are affected.