Second Hard Drive not detected in windows 10 - fixed

Apr 22, 2015
I've never run into this issue before while repairing laptops. I have a Dell Inspiron 17R 7720 laptop with an i7 CPU and 16 gigs of ram. Has room for 3 drives: standard 2 SATA slots and a msata slot. I installed a fresh installation of Windows 10 Home on a Samsung SSD 250GB drive using UEFI after updating to the latest bios version.

In the extra SATA slot, I installed the second hard drive, a Toshiba 1TB spinner. It's recognized in the bios but not windows 10 and not in device manager. After some googling, I found the solution:

If the drive is not showing up in the Device Manager try the following:
Step1: Right-click the Start button > Command Prompt (Admin)
Step 2: Then, at the command prompt type the following ( you can copy and paste) and press "Enter":
reg.exe add "HKLM\System\CurrentControlSet\Services\atapi\Controller0" /f /v EnumDevice1 /t REG_DWORD /d 0x00000001
Step 3: Restart the computer.

This worked. Like I said, I've never run into this before. If its not detected, I simply go to disk management and initialize the drive there, but it was never shown there or in device manager, only in the BIOS. Maybe it was because I installed windows 10 with only the SSD, and installed the 1TB drive after I got windows 10 running with all the updates/drivers?

Just wanted to post this in case someone else ran into this problem. ... 6adbf46527