Solution for unrecognized hard disk after upgrading win10 system

Recently, Win10 preview version 9879 was released. Many win10 users are busy upgrading, but they also encountered many problems. Some people reported that the upgrade encountered obstacles and could not be upgraded. There are also some difficulties that the hard disk cannot be recognized, and although there are so many problems, the Microsoft official did not give a specific reply. Today, Xiaobian has compiled the reason that the hard disk cannot be recognized after the win10 upgrade. The way, I don't know if it works for the computer, but before the official reply, you can try this method!

Some people solve this problem temporarily by installing Intel RST driver and Linux image recovery. . However, the solution is not the focus of this article. If you encounter the same problem after upgrading Win10, you may wish to refer to the following.
Cause Analysis
PUIS (Power-up in standby), the hard disk will enter the standby mode, and when the ATA command is received, the rotation is started to achieve maximum energy saving.
The Windows 10 Preview will open PUIS mode each time it is launched. Need to be reminded that some hard drive manufacturers have blocked this feature and will not be affected by this. IDE mode does not support on-demand booting and will not be affected by this. As for the Linux image, the repair process will turn off the on-demand boot (PUIS) state, and some hard disks may still be affected again after the power is turned off.
Workaround
Once the hard drive enters the on-demand boot state, the hard drive will no longer respond to the power/hardware/operating system boot request. If you need to re-enable the hard disk, you need to first send the Set Feature command through the ATA standard interface. The command is 0xEF, and then you can call the 0x86 command to turn off the PUIS state. Or call 0x07 to instruct the hard disk to spin start when receiving power supply.
This problem should be encountered by many users. It is a relatively common problem. Maybe Microsoft will fix this vulnerability afterwards. If you encounter this problem, please try it out!