checking in, this is also a problem on my 750JH (seems to be the only problem with my upgrade). My MaxxAudio seems to be completely missing, unlike OP. (To clarify, there is no maxxaudio executable in my system drive.

Upgrade went well hardware wise on my 750JH, only 2 problems.1. my user profile had all of its data stored on the D drive, so windows threw a fit and sent me to a temporary profile for a while. After restarting, this fixed itself, it went back to OOB...