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

The DATA XPG SX8100 NVMe SSD is not suitable for installation in the Alienware 15 R2, whose Specifications, Storage says system board interface is only for SATA solid-state drives.

Please click on Kudos to say thank you for response from another user. Please share an update on progress, so that other users derive benefit from your experience. Thank you. 

You are correct that the 15 R2 does support NVMe (which is indeed usually used interchangeably with PCIe) drives.

You may want to ensure your system has the latest BIOS release for your model.  If it does, and the drive still does not work, you may want to verify that the drive itself has the latest firmware on it.  You'll very likely need another system to make that verification unless the revision is indicated on the drive label itself.  XPG may also have some suggestions.  

Was there another NVMe drive in the system before this point?

Hi @crimsom 

i  go through the specs but it did say it can utilize M.2 PCIE SSD. This is the same as M.2 NVME right? 

Let's step one at a time.  Yes, this system does indeed fully support NVMe drives.  There's a link below from the forum that confirms it.   And yes, it is possible that if you don't have the most current BIOS, you may have issues -- start there.  It's also possible the drive needs a firmware update to function correctly.  

What OS is on the current hard drive - and is it booting with secure boot on?  .

https://www.dell.com/community/Alienware-General-Read-Only/How-do-I-get-a-NVMe-drive-working-on-the-Alienware-15-R2/td-p/5514424

Hi @crimsom 

Based on my understanding this statement Two M.2 PCIe/SATA drives there is 2 M.2 PCIe slot. I saw it myself that there is indeed 2 m.2 slot there and the ssd clicke perfectly in place. Or dors this probleM lies with my laptop not having the latest BIOS installed?

Hi @JuGaM  the terminology can be confusing. The system board has a general purpose M.2 PCIe socket, but its (information highway) bus is only designed to accept SATA drives. To use NVMe drives, a different system board is required.  

Hi @JuGaM  the Dell 15 R2 Specification says Two M.2 PCIe/SATA drives. NVMe are not SATA. 

Hi @ejn63 thanks for the reply. No, there is only HDD inside the system. I tried with both HDD connected and disconnected but the system still unable to boot.

@ejn63 there is windows 10 loaded into the hard drive. Secure boot is currently disabled. Should it be enabled?

Hi @JuGaM  you have had more than your fair share of my free time. Wish you all the best at fixing your problem. 

Hi @crimsom from my reading in some of the forum posts, it is confirmed that this mobo does accept nvme ssd. I read it before i make the purchase. Now just wondering if this has got to do woth my bios not updated.