I have an Airport Extreme and an Airport Express. I used to have the Airport Extreme set so that the 5 GHz antenna was 802.11n only, and the 2.4 GHz was 802.11bgn (I think - at least g and n). This was giving me good transfer speeds on my MacBook, but lousy on my Windows laptop. The MacBook used the 5 GHz antenna, and the Windows laptop was only able to use the 2.4 GHz antenna. I suspected that the poor transfer rates on the Windows laptop were because the 2.4 GHz antenna was being used by a variety of devices, some at 802.11n and some at 802.11g. I read somewhere on the internet that mixing speeds like this reduces performance. Can I set the Airport Extreme to use 802.11n on both antennas (this would work for both laptops), and then extend my network using the Airport Express to handle all the 802.11g devices in my house? I can extend my network using the Airport Express, but when I do I can't see any settings to make it 802.11g only. Thanks for your help!