Quick fix — CHKDSK

chkdsk C: /f /r /x

Schedule it to run on next reboot for the system drive. For data drives, run it live.

TestDisk for partition issues

If a partition is missing or shows as RAW in Disk Management: download TestDisk (cgsecurity.org) → Analyse → Quick Search → Write. This rewrites the partition table non-destructively and is the correct tool for "Drive needs to be formatted before use" errors.

Disk2vhd — image first

Before any repair attempt on a drive with failing health: use Disk2vhd (Sysinternals) to image the entire drive to a VHD file. Repair the image, not the original, if the drive is unreliable.

RAW partition recovery

If CHKDSK and TestDisk fail to fix a RAW partition: ZAR (Zero Assumption Recovery) and R-Studio can read raw sectors and recover files even without a valid filesystem.