unable to update drivers in DFU mode

Hello everybody, recently i was working on a project with my blueSMIRF for the first time, and all of a sudden my arduino would not work,with or without the BlueSMIRF. I tried to go back to the basics and just upload a simple LED flashing program to my arduino via the serial USB cable, but my arduino was not being detected by the arduino environment. I went into the Device Manager (Windows 7) and looks for my arduino under the Ports tab, but it was not there, rather, it was under the Other Devices. I had never seen it there before. I figured something was wrong with the drivers, do I tried to reinstall the latest drivers, but it would not work. That's when I noticed that the arduino was no longer listed as "Arduino Uno" but was now listed as "Arduino Uno DFU". I do not know what this means other than that I have heard some people talk about its relationship with firmware or something like that :~ . I was just wondering what I have to do to get my arduino back to normal and out of DFU mode.

I am having a similar issue...I connect the Arduino Uno board to the USB port and windows 7 does not recognize it; it never shows up in the Device manager. I can put the board into DFU mode by touching the 2 pins by the USB port together and then the device shows up in the Device manager as "Arduino UNO DFU". When I unplug it from the USB and back again it no longer appears in Device manager.

I have a second board and it works just fine. So how do you reset the board back to factory settings?