Big dell trouble

Hello,
hi any one i just read a lot of the solutions to all the problems that was solved and thats great but hear mine. i got a virus on my dell 3100 so i had a pal come in and wipe my drive and we reinstalled another operation system which went smoothly but any time i try to play music via cd or even run the sample music i keep getting"audio device not installed"or windows media player cant play file its either theres no device installed or its being used by another program.how can i fix it or where exactly can i get the compatible driver or drivers for my audio thanks