My m-audio fast track usb interface has been working but all of a sudden lately my computer recognizes it when I plug it in but the interface will not pick up a signal from a direct line or from a mic so I can't record anything.

Hello, try going into Sound & Audio Settings through control panel. From there, click on the Audio Button. Toward the bottom on the left, UNCHECK the box that says 'USE ONLY DEFAULT DEVICES'. Then Under RECORDING section, pull down the drop menu and select M-Audio. And Click APPLY & OK to close. I would reboot and it should be working after that.. ok? Good Luck & PLEASE DON'T FORGET TO RATE MY SUGGESTION, OK? THANK YOU :)