A missing partition can appear as unallocated space, RAW, or a drive letter that suddenly vanished. Do not create a new partition in the same space. First confirm the physical disk and protect important files.

Official Tools#

TestDisk is free and open source. It is powerful because it can write partition-table changes. That also means you must confirm every disk and partition before using Write.

Stop Before Software Recovery When#

  • the disk clicks, powers down, or disappears;
  • its capacity is wrong;
  • more than one disk in the computer has the same capacity and you cannot identify the source;
  • the lost data has legal, business, or irreplaceable value;
  • the disk was part of RAID, Storage Spaces, or another multi-disk set.

Complex arrays require the original disk order and configuration. Do not treat one member as a normal standalone disk.

Confirm the Disk Layout#

Open Disk Management and record:

  • physical disk number;
  • model and total capacity;
  • current partitions and file systems;
  • the location and size of unallocated space;
  • whether the disk uses GPT or MBR.

To find the partition style, right-click the left-hand Disk 0, Disk 1, or similar disk label, open Properties > Volumes, and read Partition style. Take a screenshot. Do not initialize or create a simple volume.

Start TestDisk Safely#

  1. Download and extract the stable TestDisk package.
  2. Run TestDisk as administrator.
  3. Create a log.
  4. Select the physical disk by model and capacity.
  5. Accept the detected partition-table type unless reliable evidence shows it is wrong.
  6. Select Analyse.
  7. Run Quick Search.

TestDisk may show old, deleted, overlapping, or incorrect candidates. Finding a partition is not enough.

Validate a Candidate Partition#

Highlight a candidate and press p to list files. Press q to return to the partition list.

Check:

  • expected top-level folders;
  • correct filenames;
  • plausible file sizes;
  • folders from both early and recent use;
  • whether the partition start and size match the former layout.

To copy files, highlight an item, press : to select it, and use uppercase C to copy the selection. Browse to a folder on another physical drive and press C again to confirm the destination. TestDisk shows the available keys at the bottom of the screen; follow that display if a later version differs. Open the copied files before changing the partition table.

Use Deeper Search Only When Needed#

Run Deeper Search when Quick Search does not find a valid candidate. It can take much longer and may return several historical partition records.

On an MBR disk, * means bootable primary, P means primary, L means logical, and D means deleted. GPT layouts do not use the same primary/logical arrangement. Do not change status letters merely to make a partition visible. Partitions must not overlap, and their combined layout must match the former disk.

Delay the Write Step#

Use Write only when:

  • the physical disk is confirmed;
  • every intended partition is present, correctly typed, and non-overlapping;
  • important files have already been copied;
  • you have a recovery path if the change fails.

If any point is uncertain, keep the source unchanged and recover files instead. PhotoRec can recover content when the original partition structure cannot be safely restored, although filenames and folders may be lost.

Check the Copied Files and Disk Layout#

After copying files or restoring the partition:

  1. Restart Windows only when TestDisk instructs you to do so.
  2. Confirm the expected capacity and file system.
  3. Open critical files from several folders.
  4. Back them up immediately.
  5. Check the disk for recurring hardware errors.