I orignally had a dual boot system and it ran great. I no longer had a need for a dual boot system and removed my second HD. I changed my jumper setting and got it running great with the single hard drive. Now I am getting the error " primary boot device 0 not found. I thought it was the hard drive so I changed out the HD and get the same error with 3 different HDs. I went into system setup and it says "unknown device" for device 0. I have tried several different things and no luck. Any suggestions.