Quick answer (for people who know what they're doing)
Open Command Prompt as Admin, run chkdsk E: /f (replace E with your drive letter). If that fails with 'RAW' filesystem, use TestDisk to rebuild the partition table. Don't format unless you've pulled the files off first.
Why this happens
Your external drive isn't broken — the partition table is. What's actually happening here is that Windows can't read the sector that tells it where the files start. So it defaults to 'Hey, this thing has no filesystem, wanna format it?' This usually happens after you yank the cable out without using 'Safely Remove Hardware' (guilty as charged), or after a power surge during a write. The data is almost always still there — you just need to fix the map.
Before you do anything
Stop. Don't format. Every person I've helped who formatted first lost everything. The real fix is repairing the partition table, not wiping it. If you format, you overwrite the master boot record (MBR) or GUID partition table (GPT), and the original data becomes much harder to find.
Step 1 — Run chkdsk (the easy try)
- Connect the drive. Note the drive letter (let's say D:).
- Right-click Start → Windows Terminal (Admin) or Command Prompt (Admin).
- Type
chkdsk D: /fand press Enter. - Wait. It'll scan the drive and try to fix filesystem errors.
If it finishes and says 'Windows has made corrections,' restart and reconnect the drive. You're done. If it says 'The type of the filesystem is RAW,' move to Step 2.
Step 2 — Use TestDisk (the real fix)
TestDisk is free, open-source, and it has saved my ass more times than I can count. It doesn't write anything until you tell it to.
- Download TestDisk from cgsecurity.org. Portable, no install needed.
- Extract the zip. Run
testdisk_win.exe. - Select 'Create' for log file (just press Enter).
- Pick your external drive from the list — make sure you pick the right one. Size helps you identify it.
- Select 'Intel' for MBR partition table (most external drives under 2TB use this). For drives over 2TB, pick 'EFI GPT'.
- Choose 'Analyse' → 'Quick Search'.
- Wait. It scans for lost partitions. You'll see a list of found partitions — the one you want shows the correct size and 'NTFS' or 'exFAT'.
- Highlight it → press 'P' to list files. If you see your folder structure, you're golden.
- Press 'Q' to go back, then select 'Write'. TestDisk writes the corrected partition table to the drive.
- Reboot. Plug the drive back in. It should show up normally.
Step 3 — Can't see files in TestDisk? Try PhotoRec
If TestDisk finds nothing or shows garbage, the partition table might be too corrupt, or the drive got formatted already. Use PhotoRec (same download) to recover files by scanning the raw data.
PhotoRec doesn't care about partition tables — it reads the drive byte by byte and grabs files based on headers (like JPEGs start with FF D8, ZIPs with PK). It'll dump everything into a folder you choose. Takes hours for a 1TB drive, but it works.
Alternative fixes if TestDisk fails
- Change USB port or cable. Sounds stupid, but a loose connection can make the drive show as RAW. Try a different cable, or plug it directly into the motherboard USB port (not a hub).
- Check in Disk Management. Press Win+X → Disk Management. If the drive shows 'RAW' but has a healthy status, TestDisk is your best bet. If it shows 'Unallocated,' something physically failed — you need professional recovery (expensive).
- Use Linux to read it. Boot from a Ubuntu Live USB. Open 'Disks' app, mount the drive, and see if you can copy files. Linux sometimes reads drives Windows gives up on.
Prevention tip for next time
Always click 'Safely Remove Hardware' before unplugging. Or, if you're lazy like me, at least wait 5 seconds after the last file copy finishes before pulling the cable. That 5 seconds lets the write cache flush to the drive. The real cause of this error is interrupted writes — the partition metadata doesn't get written fully, so the drive boots up confused next time.
One more thing: if you use 'Quick Remove' policy (set in Device Manager under the drive's Policies tab), Windows doesn't cache writes at all. It's slower but safer for external drives you yank often.