Recover a Lost Partition with DiskGenius

Why partitions disappear

• An interrupted resize, move or conversion left the table inconsistent.
• Someone deleted the wrong volume in a partitioning tool or during a Windows installation.
• The partition table or boot sector was corrupted by an unclean shutdown or a power cut.
• A USB enclosure or controller failure caused the disk to be re-read incorrectly.
• Malware or a bad driver damaged the disk's opening sectors.

In all of these the file data is typically untouched. What is missing is the pointer to it.

First, do no harm

1. Do not initialise the disk. Windows will offer to; that offer rewrites the table you are trying to recover.
2. Do not create a new partition on the space where the old one lived.
3. Do not run repair utilities that write to the disk before you have looked at it.
4. Do not write anything to any part of that physical drive.

Search for the lost partition

1. Open the program as an administrator and select the physical disk, not a volume.
2. Start the partition search function. It walks the disk looking for the signatures that mark the beginning of a file system.
3. Each candidate it finds can be inspected before you accept it — check the size, file system and, most importantly, the contents.
4. Accept the candidates whose file listings look like your data, and ignore the ones that are leftovers from older layouts.
5. Save the rebuilt partition table only when the results match what you expect the disk to contain.

Verify by contents rather than by size. Old, long-superseded partitions often still leave detectable traces, and accepting one of those instead of your real volume just adds confusion.

If the table cannot be rebuilt

Sometimes too much has been overwritten for the layout to be reconstructed. That is not the end of the road — you can still extract the data.

1. Run a full scan of the whole physical disk rather than a partition.
2. Let the signature-based search work through the unallocated area.
3. Preview results to identify what is intact, accepting that names and folders may be lost.
4. Recover everything you need to a different physical drive, then repartition the original disk from scratch.

After recovery

• Check the file system on the restored volume before writing new data to it.
• Work out what caused the loss. A partition that disappeared during a resize suggests a power or stability problem worth fixing.
• Run a health check on the drive — hardware trouble sometimes shows up as table corruption first.
• Set up a backup, because the second occurrence is always more expensive than the first.

Telling partition loss apart from drive failure

The symptoms overlap, and the response differs completely. A lost partition usually presents as a drive that is visible in disk tools with its correct capacity, but shows as unallocated or unformatted, while the machine is otherwise quiet and responsive. Hardware failure presents as noise, very slow reads, a capacity reported incorrectly, or a disk that disappears mid-operation.

If the signs point at hardware, do not run repeated partition searches. Image the drive first and search the image instead, and read the health check guide before deciding anything else.

Working with multiple candidates

A search across an older disk often returns more results than there were volumes, because previous layouts leave traces behind. Accepting the wrong one produces a volume that mounts but shows unfamiliar or partly broken contents.

• Judge each candidate by its file listing, not by its size.
• Prefer the candidate whose folder names match your memory of the drive.
• Ignore results that overlap each other — they cannot all be correct, and the one whose contents you recognise is the real volume.
• If two candidates look equally plausible, extract the files you need from one rather than committing a table you are unsure about.

External drives and enclosures

A large share of apparent partition losses on external drives are not losses at all. A failing enclosure, a marginal cable or a controller that reports the wrong geometry can make a healthy disk look unpartitioned. Before rebuilding anything, take the drive out of the enclosure and connect it directly, or try a different enclosure. It is common for the volume to reappear untouched.

The same applies to drives that were formatted by a NAS, a media player or a camera. Those devices sometimes use layouts Windows does not read, and the partition is present and perfectly intact — just not in a form Explorer recognises.

Frequently Asked Questions

Can I recover a partition deleted during Windows installation?

Often yes, provided the installer did not go on to write large amounts of data over that region. Stop the installation and search for the partition before continuing.

Does recovering a partition restore folder structure?

When the table is rebuilt successfully, yes — the volume returns as it was. Signature-based recovery, by contrast, returns files without their original names and paths.

Why does Windows ask me to initialise the disk?

Because it cannot read a valid partition table. Decline the offer; initialising overwrites exactly the structures you need recovered.