Hi [NAME] Ruiz welcome to this free user-to-user Alienware laptop discussion forum.  Support for Alienware x17 R2 internal Storage says slots only accept fast or ultrafast NVMe SSD cards and by default these internal slots do NOT accept slow SATA SSD cards.  Crucial System Advisor database says Alienware X17 R2 | Memory RAM & SSD Upgrades | Crucial.com. Search internet for discounted SSD cards, etc.  Use laptop External USB ports and external enclosure to access external slow SATA SSD cards. Search internet for discounted external enclosures. 
Someone knows why my Alienware x17 R2 doesn’t recognize my WD BLUE 3D NAND SATA SSD M.2 2280? I wanted to upgrade the storage of this x17 R2 since it came with a Samsung 1TB SSD M.2. But when I switched the Samsung SSD to WD Blue SATA SSD M.2 2280, my x17 R2 doesn’t recognize it? What is the best solution? 
x17 R2, WD Blue SATA SSD M.2 2280 not recognized