Setting up backup after a reformat: the OneDrive folder-backup trap

The aim of this guide is that you never need to re-read "What to sort out before you format". But first, see what the backup Windows already switched on is doing.

Last updated 2026-09-22

What Windows already turned on: OneDrive folder backup

Install Windows 11 with a Microsoft account and setup often turns on OneDrive’s "folder backup". The real location of Desktop, Documents and Pictures moves under C:\Users\name\OneDrive, and everything you put there uploads. It is called backup, but if you do not know it is on, the following happens.

"Your OneDrive is full"

The free allowance is 5 GB. A few videos on the Desktop are enough to exceed it, sync stops, and the notification keeps coming. With a Microsoft 365 subscription (1 TB) it is a non-issue; without one, this nag arrives in the first week after every reformat.

Two Desktops

Explorer shows "OneDrive\Desktop" and "This PC\Desktop" separately. Turn folder backup off and on a few times and files scatter between the two until nobody knows where anything is.

Files with a cloud icon

With "Files On-Demand" on to save space, files you have not opened in a while are removed from the PC and kept only in the cloud (the cloud icon). Without internet they will not open, and if you copy them to an external drive believing it a backup, you copy empty placeholders.

"Deleting here deletes everywhere"

Sync is not backup. Delete a file from the Desktop and it is deleted from OneDrive too (kept 30 days in the recycle bin). That helps with accidental deletions, but a file encrypted by ransomware uploads just the same.

Keep it on or turn it off?

1. 1

   You have Microsoft 365 → keep it, and use it knowingly

   1 TB holds Desktop, Documents and Pictures with room to spare, the same files appear on other PCs and your phone, and the 30-day recycle bin and version history are genuinely useful. Just decide on Files On-Demand — leave it on for a laptop, and mark anything you need offline as "Always keep on this device".

2. 2

   Only the free 5 GB → turn folder backup off

   OneDrive icon in the taskbar → Settings → Sync and backup → Manage backup, and stop backup for Desktop, Documents and Pictures. The files stay in the OneDrive folder, so afterwards move what is in OneDrive\Desktop to This PC\Desktop yourself. Then there is one Desktop again.

3. 3

   You do not use OneDrive at all → unlink

   OneDrive Settings → Account → Unlink this PC. The program stays but sync stops; remove it under Settings → Apps to be rid of it. Note that the Windows Backup app’s settings sync goes with it.

A backup you can actually restore from

There is one test of a backup: if the whole PC vanished (theft, fire, disk failure, ransomware), could you get everything back? Sync follows deletions and encryption along, so it cannot pass that test alone. Any two of the three below will.

External drive + File History

The automatic backup built into Windows. Control Panel → File History, choose the external drive, and it copies Documents, Pictures and Desktop hourly, keeping previous versions. Just leave the drive plugged in. Against ransomware, unplugging it between backups is safer.

Cloud (OneDrive, Google Drive, Dropbox)

The only copy that survives the PC disappearing. As above it is sync, so against accidental deletion and ransomware you rely on the recycle bin and version history. All three keep about 30 days of deleted files, and OneDrive can roll everything back when it detects ransomware.

System image

A complete copy of Windows, programs and settings. When a disk dies, restoring the image to a new one skips the whole reformat-and-reinstall. Control Panel still has "Backup and Restore (Windows 7)", and tools such as the free Veeam Agent are more convenient. An image goes stale, though, so it does not replace file backup.

Phone photos

Handle separately. Turn on Google Photos, iCloud or OneDrive photo backup on the phone and they survive regardless of the PC. Avoid a situation where photos moved to the PC are the only copy.

Thirty minutes after the reformat

1. 1

   Decide on OneDrive folder backup

   By the rule above. Leave it undecided and the storage nag comes in the first week.

2. 2

   Pick one place for your files

   D:, the OneDrive folder or Documents — one "my files live here" makes backup simple. Using the Desktop as a storeroom is what makes backup hardest.

3. 3

   Dedicate an external drive and turn on File History

   Twice the size of your data is plenty. Once on, you can forget it.

4. 4

   Attach one cloud

   Wherever you already have an account. At least Documents and Pictures should go up.

5. 5

   A month later, restore something

   Roll one file back to a previous version in File History and download one file from the cloud. A backup you have never restored from is not a backup.

Frequently asked