XPS 8930, SSD drive won't show

Need lots more info:

1. Exact PC model
2. Version of Windows
3. Is this a newly installed SSD?
4. Is this an NVME or SATA SSD?
5. In BIOS setup, is SATA Operation set to RAID or AHCI?  Don't change this setting!
6. Did you load Windows on this SSD?
7. If it's not the boot drive (C:) (Windows not on this SSD), did you format this SSD?
8. If #6 is "Yes", did you disconnect any other drive that also has Windows on it?

On certain PC models, Dell installed a small capacity solid state to use as hard drive cache.  If that was the case, you just leave it alone and do not make change to configuration or else the C drive won't boot. 

@Chino de Oro​ how do I know if this is one of those drives or not. She ordered this pc (so she said) special with what she wanted it to have. 

For better assist, more accurate with resolution, and as the other poster mentioned, you need to provide more information about the system and the components.  

You can check the drive model and capacity.  If it's 32 GB or less, that is a cache drive.

@CardFan58 To help your friend and to know more about her PC ask your friend to find the Service Tag for the PC. The Service Tag should be on a label attached to the back of the PC and is usually a combination of seven numbers and letters. With the Service Tag, so to https://www.dell.com/support/home/en-ph and enter it under "Identify your product or search support". In the resulting search results, there should be a quick link to "View product spec" which will list the system configuration as it left the Dell factory. For privacy reasons do not post the Service Tag here.

@Vic384​ ok i did that and it list the ssd drive like it should but not in the files  menu  and  its in the devices list but i cant access it.

@Chino de Oro​ its aa 1 tb drive

this is what it shows for the drive..................SSDR,1TB,P34,80S3,TSH,XG5

@RoHe​ its an xps8930 and the ssd is NVME windows was loaded on the sata 2tb drive i havent do anything to the ssd drive

Dell does not use large capacity SSD for cache drive.  Your system issue could be with storage controller settings.  Check SATA operation mode, if RAID is Enable, you need to change it to AHCI.

Follow the process below to change RAID to AHCI:

1. Run elevated command (as administrator) cmd.

2. Type or copy and paste this command bcdedit /set {current} safeboot minimal , your PC will start Windows in Safe Mode the next time you reboot:

3. Restart the computer and keep tapping F2 to enter BIOS setup.

4. Change the SATA operation mode from RAID to AHCI.

5. Save changes and exit Setup and Windows will automatically boot to Safe Mode.

6. Run elevated cmd again.

7. Type or copy and paste this command bcdedit /deletevalue {current} safeboot , that will start Windows in Normal Mode the next time you reboot:

8. Reboot and Windows will automatically start with AHCI drivers enabled.

Check your system to see if the SSD is available for use.  The operating system will perform better if being installed on the solid state drive. 

@Chino de Oro​It keeps telling me that command is not recognized as an intern or external command 

@Chino de Oro​ this time it said the boot configuration data store could not be opened.

If the command is not recognized, it probably contained spacing error.  See this similar instructions for visual screenshots with commands.

@CardFan58 - Are you saying Dell mistakenly installed Windows on the 2T hard disk drive instead of on the NVME SSD?   

I'd bet you used parenthesis (   ) in the command instead of braces {   } and that's why it's not recognized. So try again using braces...

@RoHe​ Would dell install windows on the ssd drive and not the 2tb drive? If so why would they. Because it's faster?

They're supposed to install Windows on the SSD, not on the 2T HDD. The SSD is much faster than the HDD so performance will be better. The slower HDD is for routine data file storage.  That said, there have been occasions when they installed Windows on the HDD by mistake. That's why I asked...

Which drive is Windows installed on in friend's PC?  If you're not sure, open Windows Disk Management which will list the installed drives.  You should be able tell by drive size (eg, 2T) which physical drive has the C: partition.  This is what it looks like on my XPS 8930:

Disk 0 is my 1T HDD (D:) with only one partition for data storage.  Disk 1 is my 512 GB SSD with several partitions including C: which is the Windows operating system.