Turning off OneDrive folder backup is a change to where your working files belong. Plan the destination before clicking through the prompts, especially when Desktop or Documents contains a mix of downloaded and online-only items.

Begin by checking the correct OneDrive account and opening several recent files on the website. Resolve outstanding sync errors first. For important data, create a separate verified copy outside the folder whose backup settings you are changing. Do not make the only safety copy inside that same synced folder.

Read the destination choice

Open OneDrive settings, go to Sync and backup and select Manage backup. When you turn off a folder's backup, the current Windows workflow asks whether to keep the files only in OneDrive or only on the PC. Those choices affect which location retains the files; they are not interchangeable ways of dismissing a notification.

If you want files on the PC, online-only content may need downloading first. Microsoft describes a prompt to change such files to Always keep on this device. Check storage capacity and let the download complete before trying the change again.

On a work or school computer, an organisation may control folder backup. A greyed-out option should be discussed with its administrator instead of worked around by unlinking accounts or deleting folders.

Inspect both locations afterwards

Open the local Desktop or Documents folder and the corresponding OneDrive folder deliberately. Use the address bar to identify which location you are looking at. Check recent files and subfolders, then open representative documents from the intended destination.

Create one harmless new document in the location you now plan to use. Confirm that it behaves as expected: if backup for that local folder is off, new local files should not be assumed protected by OneDrive. Establish another backup arrangement if needed.

Leave duplicate cleanup until the new arrangement has been checked. Confusing copies are inconvenient, but deleting the wrong remaining copy is much harder to undo.

Reference: Microsoft Support.