Dear Stephen King (0307100k),
Thank you for your reply.
I see that you indicated that after opening outlook it shows that it is full and is prompting an error because the document files are saved in OneDrive. You indicated that most of the files are in your desktop and documents folders, and you are not sure if you have unlinked your account, and if you uninstall OneDrive, your files will not synchronize with your desktop files.
If you are still concerned about your sync being affected by the unlinked account and would like to re-link your account, you may need to re-download the OneDrive program to unlink the account since this is done in the OneDrive program, and then uninstall your OneDrive after unlinking it:
You can open the OneDrive program in your system, click Settings - Sync and Backup - Manage Backup to see exactly what folders you have chosen to synchronize your desktop with, you can turn off your folder options to stop the synchronization, this does not affect your OneDrive file information.
However, you should note that if you cancel the link, your desktop and other folders will show corresponding shortcuts, we suggest you open the shortcuts to copy or backup the files to other places, so that you can delete or move the shortcuts to cause file loss.
Back up your folders with OneDrive - Microsoft Support
Meanwhile, the concern that you are displaying a mailbox that shows OneDrive files are full is due to the fact that the space and corresponding information has been stored in your OneDrive web end, and you can further confirm your OneDrive space information:
You can log in to the OneDrive web end: https://onedrive.live.com/ to view the details of the storage in the lower left corner to help confirm whether your OneDrive space is sufficient.
You also indicated that you found the OneDrive folder in question by digging through the folders and wanted to confirm the impact of deleting it on your synchronized files:
Since you indicated that you found the corresponding OneDrive file information through searching and are not sure if it is due to any changes made previously and other information, we are not able to fully determine whether it will affect your OneDrive synchronization information, according to the screenshot information you shared with us to confirm that it is indeed the OneDrive folder information.
OneDrive will not sync your information after you completely delete it, and you may not keep the OneDrive program on your system, before you delete it, in order to prevent your synced files from being affected and resulting in file loss.
To prevent your synchronized files from being affected before you delete it, you can uninstall and delete the folder after you have backed up your files after unlinking it.
If you don't want to re-download the OneDrive program, you can try to find your folder information through your OneDrive web page, keep the files backed up in other places, and then delete the corresponding folders.
You can manipulate your OneDrive program and folder information according to your needs.
Hope it helps. If any update, welcome to share with us.
We look forward to your response.
Thanks for your patience and understanding.
Best Regards,
Zenobia-MSFT | Microsoft Community Support Specialist