In your BIOS check the BOOT order . and see if the hard drive with the operating SYS is first in line . if not change boot order to advantenced , tham put the HD with the OS first in line . So the BIOS sees it first , instead of the mouse , DVD burner , card reader or anything else infront of the HD.
There is a new BIOS version for this board, please try that. If your system is giving blue screen use the memory checking tools like Memtest 4.6 or Windows Memory Diag. Mostly Kingston RAM is good for these motherboards, if you can exchage it for Kingston, please do and try it once.