Your systems service manual is here: https://topics-cdn.dell.com/pdf/alienware-15-laptop_service-manual_en-us.pdf It looks like there is both a M.2 slot and a 2.5" drive bay. Both of these can be upgraded to Solid State Drives. You should prepare Windows 10 Installation Media before replacing your Drives. I've wrote in depth guides here on Windows 10 Installation: https://dellwindowsreinstallationguide.com/windows-oem-faqs-and-downloads/