Audacity does not offer the USB input option even after TRANSPORT - RESCAN Tried all ports and added a ASIO driver for Alesis which should not be necessary as the iO2 is supposed to be Class Compliant??
Audacity is shipped without ASIO support, so unless you intend to use the Alesis iO2 with an application that supports ASIO, then I’d recommend that you remove the ASIO drivers.
Look in the Windows Sound Control Panel to see if the Alesis iO2 is enabled and working (if it is working correctly, you should see a green meter in the Record tab, jumping up and down when you input sound into the Alesis iO2.)