The HP 255 G7 Notebook Supports Either Single Drive or Dual Drive Configurations Depending on the System Board Installed. (Single and Dual Drive Options with a AMD Ryzen 3/5 xxxxU Series Processor: One 2.5" Solid State Drive or Hard Drive and/or One M.2 NGFF (2280) Solid State Drive) or (Single Drive Options with a AMD Athlon APU 3xxxU Series or A4/A6/A9/E2 Series Processor: One 2.5" Solid State Drive or Hard Drive or One M.2 NGFF (2280) SATA Solid State Drive using a M.2 Drive Bracket) Note: When the M.2 (2280) Drive is installed in models with a AMD Athlon 3xxxU series or A4/A6/A9/E2 series processor, the M.2 Drive occupies the 2.5" Drive bay by using a M.2 Drive bracket p/n L20458-001 and connector board p/n L20457-001 and Drive. If replacing the M.2 Drive for a 2.5" Drive in models with a AMD Athlon 3xxxU series or A4/A6/A9/E2 series processor, or adding a 2.5" Drive to models with a AMD Ryzen 3/5 xxxxU series processor, you will need the 2.5" Drive caddy p/n L20455-001 and connector board p/n L20454-001 and cable p/n L20456-001 for installation. (The M.2 Drive board supports SATA only Solid State Drives and the M.2 slot on the AMD Ryzen 3/5 xxxxU series system boards support SATA and PCIe NVMe Solid State Drives)