This Machine Comes in 2 Different Drive Options from HP and Supports Single Drive Configuration Only. (One 2.5" Solid State Drive or Hard Drive) or (One M.2 NGFF (2280) Solid State Drive using a M.2 Drive Bracket) Note: When the M.2 (2280) Drive is installed, the M.2 Drive occupies the 2.5" Drive bay using a M.2 Drive bracket. If replacing the M.2 Drive for a 2.5" Drive, you will need the 2.5" Drive mounting bracket p/n xxxxxx-xxx and cable p/n 865205-001 for installation. If replacing the 2.5" Drive for a M.2 Drive, you will need the M.2 Drive mounting bracket p/n 856067-001 and connector board p/n 856210-001 and cable p/n 856202-001 for installation. (The M.2 Drive connector board supports SATA only Solid State Drives)