Reason 1, the motherboard chipset controls the onboard network card, video card, USB and other interfaces, but also control the motherboard of the IDE or SATA hard disk data interface, if the interface is not damaged, then this problem is generally due to the motherboard chipset caused by the motherboard chipset caused by the cause of 2 times to recognize the hard drive, It is recommended that ghost Win7 system users try to replace the motherboard or repair the motherboard to resolve it.
Reason 2, there is a relatively rare fault, the boot sector of the hard drive is actually corrupted, so there will be logical problems so that each boot can be opened 2 times to recognize the problem of hard disk, but because it is a logical problem, so the second time when the power is restored to normal, in fact, to solve this problem is relatively simple, You only need to reformat the partitioned hard disk, and then reinstall the system to resolve it. (PS: You need to format and then reload, not directly reload).