[TheMusicGeek]

I strongly doubt that was the version I paid for originally as I try to keep up with bug fixes. MTU's own blog clearly states "you can install the fixed upgrade(s) even if they were physically made available months or years later." so it shouldn't matter anyway. When I replaced my office computer I uninstalled all MTU software from the old machine and reinstalled it on the new one. I was able to reinstall Microstudio 4.21 and Keyright 2.20 without issue but not 4.23 and 2.21. As per MTU the 4.23 is needed to correct the pfc.sys error I have. Keyrite is not that important as I rarely use it but like I said, I try to keep up with the fixes.