"hkcu\volatile environment" missing, hkcu\environment not read

Question

This question is very similar to this one. Suddenly, my "HKCU\Volatile Environment" keys disappeared, and my system no longer reads HKCU\Environment unless I reset it explicitly using SETX (which I think sends a WM_SETTINGCHANGE to all active processes). I reset the volatile environment keys manually, but they are not being determined dynamically; they just stay at the values I set. If I do nothing some of the typical volatile environment keys are generated in HKLM\System\CurrentControlSet instead, but HOMEPATH & HOMEDRIVE are missing, and these process variables don't show up as system variables, although they show up in cmd.exe if you type SET. Explorer does seem slow to boot, but even if I run msconfig (haven't tried autoruns yet) , and select diagnostic startup, I still get the same issue. Can somebody please help me? Using a startup batch file to trigger a read of the user variables is only a temporary fix. Thanks!