gamemd-spawn.exe can't be used for Ares/MO, you need files from The Ultimate Collection of C&C, The First Decade or the original CD release of Yuri's Revenge.
Thanks Speeder. I'll look into the ultimate collection, thanks again.
Having some issues getting this mod to work. I have the CnCNet version of YR. I copied my existing game folder and put the MO3 files into the new directory. I followed the instructions in the first post to set the relevant files to run as administrator. When I first tried it I got an error saying the file could not be found as my gamemd file is named as 'gamemd-spawn.exe'. I tried to rename the file to gamemd.exe but it then asks me to insert my YR CD which I do not have and haven't needed it to play on CnConline or Westwood servers as my serial is already registered. Should I download ISOs and mount them that way and use my own serial to install again? If so, is it possible to still use the CnC servers to play online?