Atheros ar928x in Asus m50vm

brand new router DGL-4500; in 802.11 g/n mode, 2.4gz, wpa personal, checked for router bios update...it is the latest update; vista 32 bit; device manage/look at properties for adapter it only lists b mode. My son is doing homework right now. Not sure why it is listed in the router as connected devices because router is said to be in b mode. I haven't been able to confirm if this adapter was designed to perform in n mode or if the setting I saw is dynamic. I can try to force n mode by changing the setting in the router and 5 hz, then see if his laptop will connect. I didn't see anywhere to change the mode for the adapter.
Do you know if this was designed to run in N mode?
If not, thanks so much for the info that it is replaceable.

I found this same scenario thread:
Atheros AR928X...No Wireless N?!?!?