What to do first
Check the Microsoft account in a browser, confirm Windows time and network access, then sign out and back in only after you know the cloud copy is current.
OneDrive and cloud files
A OneDrive sign-in problem can stop sync without affecting the cloud copy. Protect the account and verify which identity the client is using before unlinking it.
Quick answer
Check the Microsoft account in a browser, confirm Windows time and network access, then sign out and back in only after you know the cloud copy is current.
Why it happens
Authentication tokens expire, work and personal accounts can be confused, and incorrect time or cached credentials can prevent a valid sign-in.
Step by step
Safety note
Protect important files before resets, driver removal, account changes, or recovery operations. If the symptom points to hardware, repeated software changes can make diagnosis harder.
Unlinking normally disconnects the client; it should not delete the cloud copy. Still, verify the online files before changing the local folder.
Expired tokens, incorrect time, cached credentials, account policy, or a damaged client state can all cause repeated prompts.