Studio XPS M1640

I have a Studio XPS M1640 notebook it is about 10 months old,  with the Intel(R) WiFi Link 5100 AGN card I can only get it to connect using G. I have a R wireless router and my friend has a R wireless router he connects to both using N. The Intel(R) WiFi Link 5100 AGN card is N capable right? 

Thanks for the help