SSD or Hard Drive Is Not Detected in Windows
Check Disk Management
Right-click the Start button and select Disk Management.
Look for the missing drive.
A newly installed drive may need to be initialized and formatted before it appears in File Explorer.
Formatting a drive deletes existing data. Do not format a drive that already contains important files.
Check Device Manager
Open:
Device Manager > Disk drives
Verify that Windows detects the drive.
Check BIOS or UEFI
If the drive does not appear in Windows, restart the PC and check whether it appears in BIOS or UEFI.
Check physical connections
For SATA drives, inspect:
SATA data cable
SATA power cable
Motherboard SATA port
For NVMe drives, confirm the SSD is properly installed in the M.2 slot.
If a drive containing important data suddenly disappears, avoid repeatedly modifying or formatting it until the drive has been properly diagnosed.