After temporarily using my 1TB external SSD to store a clone of a 256GB internal SSD, my external SSD will only show as a 218GB drive even after format. How do I get it back to 1TB?
When you cloned the smaller 256GB internal drive onto your 1TB external SSD, the cloning software copied the exact partition structure. This means it created a 218GB/256GB partition on your external drive and left the remaining ~700GB as unallocated space. A standard format only clears the active 218GB partition; it does not reclaim the unallocated space.
Now you can first wipe the drive using Windows Diskpart, and then reformat it:
1. Open Command Prompt as Admin: Press Windows Key + R, type cmd, and press Ctrl + Shift + Enter.
2. Launch Diskpart: Type diskpart and hit Enter.
3. Find your drive: Type list disk and hit Enter. Identify your external SSD by its total size (around 931 GB). Note its number (e.g., Disk 1).
4. Select the SSD: Type select disk X (replace X with your disk number) and hit Enter. Make sure this is the correct drive!
5. Wipe the drive: Type clean and hit Enter. This instantly erases all cloning partitions.
To format it for use:
1. Right-click the Windows Start button and open Disk Management.
2. If prompted to initialize the disk, select GPT and click OK.
3. Find your external drive at the bottom, which will now show as a large black bar of Unallocated Space.
4. Right-click that unallocated space, select New Simple Volume, and click Next through the prompts to format it. [ Further reading : How to Initialize & Format External Hard Drive on Windows PC? ]
