It is in the control panel.
If not, remove it by deleting it in the system directory and allow the computer to find it again and reinstall on reboot. It may be having a resource conflict and it should sort it out by it's self. Recent additions to the system often cause this to occur and goofy drivers from Microsoft update can also cause this.
Happens all the time to me.
Were you using Media Player? My computer had a similar problem a few days ago, which was fixed when I downloaded a critical update that was for Media Player. If not, reinstall your cd burner, or the drivers for it. I am actually quite hopeless about this, but FReepers NCDave4Life and Prospero have walked me through so many crises that I sorta know what i'm doing. Also, unplugging the computer comletely and cold booting might be a good idea. Seems to work for me.