only one speaker workin with reaper

On one of my computers, Reaper is outputting to only one (left) speaker. When i play the same music file with Quicktime or Windows Media Player, it playes correctly through both speakers, so I know that the problem isn't the speaker. I tried panning left or right in Reaper and the output still only comes through the left speaker. (whereas panning left or right with quicktime or Windows media player will actually pan to the left or right) I know it must be something simple that i messed up in reaper configuration but i can't figure it out. Any suggestions will be automatically appreciated! Thanks Super Kristen

Probably some thing wrong in prefs/audio device. Check output range settings that you have two outputs, most likely 1 & 2 Then on your master channel io button check the hardware output that you have stereo output; possibly something like Output 1. analog 1/2 Your master vu must obviously be showing output on both sides

YUP ... YUP .... YUP ..... It works again! ALLS WELL! Thanks Super Kristen

saved me too 

this happened to me just now after adding a theme the io button was set to one. I googled it and this thread came up thanks