You connect an external drive, USB flash drive or memory card and Windows says: “You need to format the disk in drive E: before you can use it. Do you want to format it?” Click Cancel. Formatting doesn’t wipe your data completely, but it makes recovering it much harder. The message means Windows can’t make sense of what’s on the disk – not that your data is gone.
What the message means
Windows couldn’t find a readable file system on the disk. In Disk Management, a disk like this usually shows up as RAW. There are three possible causes:
- A damaged file system – the disk was unplugged without being safely removed, there was a power cut or an error occurred while writing. The drive itself is technically fine, the data is still on it and this is logical damage.
- Bad sectors or an ageing disk – the disk reads with errors, is slow or keeps disappearing.
- A problem outside the disk – a faulty USB cable, hub or the adapter inside the external drive’s enclosure.
What you can try yourself (risk-free)
- Click Cancel – don’t format.
- Try a different USB port and a different cable, ideally plugged straight into the computer rather than through a hub.
- Try a different computer. If the disk works there, the problem lies with the first computer or its driver.
- If the disk comes from a Mac or a TV, it may use a file system Windows can’t read (such as APFS or ext4). Try connecting it to the device you used it with.
What not to do
- Don’t format the disk – not even a “quick” format.
- Don’t run a disk check (CHKDSK) or any repair tools. They write to the disk and can overwrite the information used to locate your data.
- Don’t copy anything new to the disk or install recovery software on it.
- If the disk clicks, beeps or won’t spin up, disconnect it and don’t plug it in again – it’s mechanically damaged and every spin-up makes things worse.
When it’s a job for a professional
If the disk holds photos, documents or accounts with no backup, it’s safer to disconnect it and have it assessed. With logical damage, we can usually recover the data in-house. A disk with a mechanical fault is opened by our partner laboratory in a dust-free cleanroom.
We’ll tell you the price in advance, once we’ve assessed the disk, and diagnostics are free if you go ahead with the recovery. You’ll find prices by type of damage on the external drive data recovery page and in our guide How much does data recovery cost.
Frequently asked questions
Has formatting deleted my data for good?
Not always. A quick format mainly overwrites the file system information, so the data can often be recovered. A full format in Windows, however, overwrites the data with zeros, and then it can’t be recovered. That’s why you should stop using the disk after formatting and send it to us for assessment.
Can I use data recovery software?
If the disk is otherwise healthy (it doesn’t click, isn’t slow and doesn’t keep disappearing), yes – but install the software on a different disk and save the recovered data somewhere else, never back to the same disk. If you’re not sure what state the disk is in, it’s better to have it assessed.
My camera’s SD card shows the same message. Does this apply to it too?
Yes. Take the card out, stop taking photos on it and don’t format it, not even in the camera. Deleted photos can usually be recovered from the card.
How do I send the disk?
Put it in an antistatic bag, or at least a plastic bag and bubble wrap, so that it can’t move around in the box. Our courier will pick it up free of charge anywhere in the Czech Republic, or you can bring it to our shop in Hradec Králové.