Need help with recording quality

Version 2.0.2 Windows 7 64 bit

I’m trying to record cassette mix tapes to transfer to CD’s, recording in stereo through a USB port on a desktop. The quality of the recorded sound is very poor–very tinny, vocals too quiet on many songs, bass too quiet on many songs, etc. The sound coming out of my tape player (through head phones plugged into it) appears to be very good. The recorded sound isn’t, either before or after saving (as an .aup file) as heard from my computer’s speakers, the headphones, or after burning to a CD.
It isn’t a balance L-R issue and the Normalization effect doesn’t solve the issue. I uninstalled and then downloaded 2.0.2 again, and then downloaded 2.0.2 in my wife’s desktop (Windows 7 and newer than mine) just to make sure it wasn’t my sound card or drivers with the same results. So I must be missing something in setup preferences somewhere, but I’m at a loss to find what it is.
44100, recording level adjusted correctly. What have I missed?

You can get that if Windows thinks you’re trying to make a Skype call instead of recording high quality music. It’s Windows Enhanced Services.

There’s other ways to get this distortion, but that one’s most common.