I've never tried to make a stereo source on my pc upmixed to multichannel. With stereo sources not on my PC for example my older consoles, laserdiscs or tv i use Pro logic II because i like the voice to be from my front speaker. Never had a problem just changing the surround button to PLII on my receiver with any source other than my PC. Windows says i have support for Dolby Digital and DTS, the HD formats ect only proper multichannel sound. When i have a DTS encoded source i play it with VLC and it works the light appears on my receiver. Whenever i play a stereo encoded video on VLC i cannot select Pro Logic II on my receiver; i only get the options for Stereo, Stereo or PCM. With video i usually use multichannel sources so i've never had to upmix, with music i prefer stereo, gaming works fine in surround, only now i have a stereo encoded video that i'd like to upmix. My Pioneer VSX 527 should be able to do this.