15 R3, D Drive missing?

what update did you do?

a certain version of windows 10 (think t was 1903 but can't remember exactly) caused systems with more than 1 hdd to alter the drive letter of the second drive if it wasn't disconnected for the update.

I suggest you look in disk management to see if you see the D drive volume and if it's there under another drive letter change it back to D.

the last was the security patch on jan 12 for 1909 and up. And when I look into disk management, I only see OS (C:/), and (Disk 0 partition 1,4,5,6). No other letters have appeared. 

Hi @Smaph  welcome to this user to user forum. This is not Dell Support. 

Please share an image of your disk management. Thank you. 

Hi @Smaph  thank you for sharing your Disk Management image. To assist with our understanding of this problem, as the D drive is not a partition on the physical Disk 0, is there another physical Disk? 

Alienware 15 R3 Setup and Specifications > Specifications > Storage says there is one 2.5" bay and two M.2 2280 slots. Please share what physical disks are installed in your system. Removing the rear cover does not invalidate the Dell warranty. Usually the physical Disk(s) is securely captivated so that does not move around and become disconnected from its electrical cable connector or M.2 socket. It is possible that the other physical disk health's has failed. As your OS (C:) drive is working, guess that the 2.5" SATA III disk is not working. 

Can you also go into the BIOS and see what drives are listed on the first screen. 

It should show a list with First HDD, Second HDD, etc. If your second drive isn't listed then it may have failed. If it is listed then it is most likely a Windows issue. 

Hello! I just recently went into the BIOS and it has showed 1 HDD and 2 HDD (etc.) on the screen. 

No the right side of the list does not look like that. It says none for all of them. Ill try out a system restore. 

Ok good luck. If it says none for all of them then that's very strange. You should have at least one listed if Windows 10 is loading. 

Thank you! I will get back to you once I have completed the BIOS reset when I am able too! Also here's a quick image of how my BIOS look just for reference before. 

Hi @Smaph  thank you for sharing update. 

When BIOS says no disks installed, a BIOS reset is required.
(1) Disconnect ac adapter.
(2) Remove rear cover.
(3) Disconnect main battery (do not remove).
(4) Disconnect (CMOS) disc battery (do not remove).
(5) Remove RAM cards and look for RTCRST (Real-Time Clock Reset) text, and their metallic spots on the system board. (6) Put flat screwdriver blade across RTCRST spots on system board.
(7) If there is no RTCRST, press and hold down the power button for one minute.
(8) Replace RAM cards, reconnect main battery and disc battery, replace rear cover.

Revisit BIOS to confirm it says disks are installed. Your D drive should now be listed in This PC window. 

Please share an update. Thank you. 

Hi @Smaph  thank you for sharing update and image. 

This BIOS image shows only one disk installed. Disk Management shows one disk with just the OS (C:) partition. Guess that more than one physical disk is installed in your system, and that BIOS reset was required in the dim and distant past. Whatever triggered D Drive missing is fortuitous to get your system working correctly again. 

Before starting, you may wish to look at this Laptop's Dell Documentation and/or watch a YouTube video to become familiar with this BIOS reset process. With the rear cover removed, be careful not to damage anything.