Sound Card Error...

[talhaarfi]

doston mere computer main yeh masla aagaya hai k jab bhee main computer on karta hoon woh sound card ka driver show nahee karta...kabhi kabhar khud install hojata hai kabhi khud karna parta hai..magar jab main koi mp3 file windows media player par play karta hoon to yeh error aata hai

magar windows kee sounds chal rahee hoti hain jaisa k computer on/off honay par sound play hoti hai ...ek baat aur k taskbar se bhee volume controls ka option gayab ho gaya hai jab ussay main control panel se lane kee koshish karta hoon tab bhee nahee aata aur error aata hai
"There are no mixer devices installed in your computer"

mere pc ka soundcard bhee built in hai..
Plzzz Itd Experts help me in this matter...