We've recently received a support question of a user who could not play an MP3 file with media_play on his Windows 7 PC. MP3 however should be supported on all PCs, without needing to install a CODEC. We could not yet reproduce a problem with media_play on our own Windows 7 systems here.
Has anyone noticed a problem so far with media_play on his Windows 7 PC? If so, could you post your DxDiag output here?