Hi Charlie, I’m Pau, an Independent Advisor. Let me help you fully solve this.
Please follow to these steps:
> Restart your computer again and try the backup again.
> Get Windows updated:
Click on Update & Security > Windows Update in the Settings menu. Check for new content > Update everything > If you need to, restart.
> Make sure you are an administrator:
Select Accounts from the list of settings. Check that your name says "Administrator" under it.
> Type services.msc, press Enter, find Credential Manager, right-click it, and choose "Restart." This will start the Credential Manager service again.
> Fix credentials that aren't working:
To get rid of old or suspicious entries, go to Control Panel > Credential Manager > Windows Credentials.
> Use the Command Prompt to reset the stored credentials:
Click Start and then click Command Prompt (Admin). Hit the "/list" key. Find entries that aren't working right > Press the "/delete" key and type "for each >" Try backup again.
> Fix files in the system:
Click on Open Command Prompt (Admin) > Click on sfc /scannow > Wait until it's done, then type DISM /Online /Cleanup-Image /RestoreHealth. Wait until it's done.
> Try it out with a fresh user account:
Going to Settings > Accounts > Family and other users Add someone else to this computer > Make a local account, log in, and try the backup again.
If you follow these steps, this problem will always be fixed. If the problem keeps happening, please let me know so I can help you more.
Thanks for your time. I'm sure this will make your backup work perfectly.
Have a great day!
Warm regards,
Pau