One Laptop With Slow Speeds

I recently got AT&T u-verse, and the router/ modem it came with supports the 802.11n standard. I have 4 devices constantly connected to the router. They all can get about 10 Mbps at any time, and some of these devices are only g devices. My laptop has an N card and only get's 3 Mbps. I have done 2 virus scans that did not find one item, and the driver for the card does not have a lot of configurable settings. The cars is a realtek rtl18191SE.

Thank you.