Hello,
You do not need to update the POST on AWUSBs since they already have the latest versions.
If the USB devices aren't powered, it's probably because the AWUSB isn't connected/installed successfully.
I suggest reviewing the Quick Start Guide first:
http://ftp1.digi.com/support/documentation/AnywhereUSB_Quick_Start_Guide_10302014.pdf
If that doesn't help, look through the many AWUSB KB articles:
http://www.digi.com/support/kbase/?osvid=0&sfid=45&QueryExpr=