This is the problem - I have WinXP SP 2 - I installed K-lite codec pack - And even with that i cannot play MIDI files, not with Windows Media player, not with Media player classic nor with winamp - Curiously I can play them on Quicktime but... - I don´t want to use Quicktime... ¿Which could be my problem?
MIDI are instrument files, not realy a proper audio file hence why you can't realy play it on a normal music player. You can use Cubase, Reason, Protools (kinda), Quicktime (as you've mentioned) or any other player/music editor that supports Instruments and MIDI format. Give Audacity a go... but i havn't tried it myself yet..
Sorry for taking a while to respond.. So i assume all other audio types work as per normal then.. try reinstalling your audio codecs: Device manager open the tree to Sound, video and Games controllers Remove anything relating to Audio devices/codecs Reboot the PC and let windows reinstall it.