Boot Disk Failure

Running Windows 7 Home Premium. For three days now I have seen nothing but the error Boot Disk Failure when trying to boot up.. I can overcome it by putting the IOS 7 disk in the DVD CD drive and let it boot so that I can then run the repair on the computer. I borrowed an OS 7 install disk and the same thing happens. After a series of checking the system I am informed that nothing wrong was found. If I leave the disk in the drive, even through rebooting, the machine runs just fine. If I take the disk out of the drive, I am dead in the water until I put it back in the drive, reboot and let the tests start over again and all is fine. Any help for me? As usual, TIA.

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Home Premium, 64 bit
Processor: AMD Athlon(tm) II X2 215 Processor, AMD64 Family 16 Model 6 Stepping 2
Processor Count: 2
RAM: 2942 Mb
Graphics Card: NVIDIA GeForce 6150SE nForce 430, 128 Mb
Hard Drives: C: Total - 465670 MB, Free - 434472 MB; D: Total - 11165 MB, Free - 2084 MB;
Motherboard: PEGATRON CORPORATION, NARRA5
Antivirus: Norton Internet Security, Updated and Enabled