Did you do it from Safe Mode? Just doing it in Windows doesnt mean it is a clean machine. Could be a driver that is infected that is preventing this. I have seen many viruses in the Driver folder for Windows. Not seen or scanned while in normal mode.
C:\Program Files\Realtek\Audio\HDA\RtHDVCpl.exe - this is just the audio driver, i uninstalled and installed the official one from the acer website and its still there, i also found a .reg key which enables autoplay but it sadly didn't work