Please help - Error code 82

I need urgent help to rectify an error while programming my DE2-115 board in JTAG and ASP modes. Whenever I use Quartus II v10.0 programmer to program the board, I am unable to detect the USB Blaster and I get the following error : Attempted to access JTAG server --internal error code 82 occurred. I didn't have this problem few hours ago. How do I solve this problem?!?! :confused: