New drive is not initialised
Why does Windows say my new hard drive is unknown and not initialized?
Written by The CommonFixes team · fact checked by CommonFixes review desk
Last updated
Short answer
A brand new drive leaves the factory as blank space with no partition table, so Windows can see the hardware but has nothing to mount. That is normal and it just needs setting up. The same message on a drive that used to work means something else entirely: the partition table has been damaged, the connection is loose, or the drive is failing. The two situations look identical on screen but the right response is completely different, so it matters which one you have. The quickest thing to try first: be certain whether the drive is new or used — If it is fresh out of the box, carry on to the next step. If it held your files and now shows as not initialized, stop. Do not initialise it, because that writes a new partition table and makes recovery much harder. Skip ahead to the recovery step instead. Most people are done in about 15 minutes.
Full walkthrough below: 7 steps for Windows, rated careful.
Sounds like this
- •The drive does not appear in This PC at all
- •Disk Management lists it as Unknown, Not Initialized
- •The space beside it is shown as Unallocated
Why it happens
A brand new drive leaves the factory as blank space with no partition table, so Windows can see the hardware but has nothing to mount. That is normal and it just needs setting up. The same message on a drive that used to work means something else entirely: the partition table has been damaged, the connection is loose, or the drive is failing. The two situations look identical on screen but the right response is completely different, so it matters which one you have.
Work through these in order
0% done- 1
Be certain whether the drive is new or used
If it is fresh out of the box, carry on to the next step. If it held your files and now shows as not initialized, stop. Do not initialise it, because that writes a new partition table and makes recovery much harder. Skip ahead to the recovery step instead.
- 2
Set up a new drive in Disk Management
Right click Start, choose Disk Management. The new drive appears at the bottom as Disk 1 with a black bar. Right click the disk name on the left, choose Initialize Disk, and pick GPT unless the drive is under 2 TB and needs to work in a very old machine. Then right click the black unallocated bar, choose New Simple Volume, click through the wizard, pick NTFS and give it a letter and a name. It shows up in This PC straight away.
- 3
Check the cable and power if nothing appears at all
Inside a desktop, reseat both the SATA data cable and the power lead, and try a different SATA port and a different cable; SATA cables fail more often than drives do. For an M.2 drive, make sure it is pushed fully into the slot and the retaining screw is in. For an external drive, use a different cable and plug it straight into the laptop rather than a hub, and prefer a powered enclosure for anything 3.5 inch.
- 4
Make sure the BIOS can see it
Restart and press F2 or Delete for setup. If the drive is not listed there, Windows will never see it and the problem is physical. For an NVMe drive, some boards disable a SATA port when the M.2 slot is used, so check the manual for shared lanes.
- 5
Recover the data first if the drive used to work
Connect it as a second drive, then run TestDisk, which is free, and let it analyse the disk and rewrite the lost partition table. If you would rather point and click, Recuva or the free tier of Disk Drill can copy files off. Always copy the recovered files to a different drive, never back onto the one you are rescuing.
- 6
Check the drive's health before trusting it again
Install CrystalDiskInfo and look at the status. Caution or Bad, or any reallocated sector count above zero on a spinning drive, means it is on the way out. Copy your data off now and replace it. A drive that has lost its partition table once for no clear reason usually does it again.
- 7
Give an external drive its own letter
If Disk Management shows it as healthy with a size but no letter, right click the partition, choose Change Drive Letter and Paths, Add, and pick a letter. A missing letter alone can make a perfectly good drive invisible in This PC.
If none of that worked
If the drive clicks, beeps or spins up and down, switch it off and do not keep trying. Every extra minute of power lowers what a professional recovery service can get back, and that is the only realistic option once the mechanics are failing.
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This guide was last updated on 10 August 2026. If a step no longer matches what you see on screen, tell us on the contact page and we will test it again.
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