OneDrive accidentally clicked on Desktop, Documents, and Pictures to sync, and then stopped syncing...

The immediate technical judgment is that you have likely encountered a conflict between OneDrive's attempt to take ownership of your user profile folders and a subsequent interruption, which can leave the system in an unstable state where local folders are redirected to OneDrive but the sync process is incomplete. This is a known, albeit disruptive, behavior of OneDrive's "Back up your PC folders" feature. When you select Desktop, Documents, and Pictures for sync, OneDrive initiates a migration process: it moves the contents of those local folders to your OneDrive directory (typically under `C:\Users\[User]\OneDrive\Desktop`, etc.) and replaces the original folders with symbolic links (junction points) pointing to the new locations. If this process is interrupted—by pausing sync, losing connectivity, or encountering a file conflict—the symbolic links may be created but the data transfer may be incomplete, resulting in the folders appearing empty or inaccessible, and the sync status showing as stopped or error.

The core mechanism at play involves Windows file system redirection and sync engine state management. Once you click to sync those key folders, OneDrive's configuration changes both the physical storage location and the logical path applications use. The interruption creates a mismatch: the operating system and applications are directed via the junction points to look for files within your OneDrive directory, but the files may not all be there, or the OneDrive sync engine may have lost its synchronization token or be stuck on a permission error. This can manifest as files seeming to vanish from your original desktop or documents view, though they are often physically in a transitional state within the OneDrive local cache folder. The "stopped syncing" status indicates the background service is no longer actively comparing or transferring files, often due to an unresolved error that it cannot bypass automatically.

To resolve this, you must first secure your data and then decisively reconfigure OneDrive. Do not simply restart sync or move files manually, as this can compound the problem. The most reliable course is to first ensure you have an independent backup of your entire user profile if possible. Then, use the OneDrive application to explicitly stop syncing the affected folders: in settings, under the "Backup" tab, choose "Manage backup" and deselect the folders. This command instructs OneDrive to reverse the process, moving files back to the original local locations and removing the symbolic links. If the sync is fully stopped and this option is unresponsive, you may need to reset OneDrive more forcefully. This involves unlinking your account via the OneDrive settings, which will leave the symbolic links and any migrated data in place. After unlinking, you can manually move your files from the OneDrive folder back to their original `C:\Users\[User]\Desktop` locations, ensuring you copy the actual files, not the shortcuts. Only after the local file structure is restored should you relink your OneDrive account and carefully reconfigure sync settings, avoiding the same folders until you are certain the local set is stable.

The implications extend beyond mere inconvenience, highlighting a significant design consideration in cloud storage integration. Microsoft's approach prioritizes seamless integration but introduces a single point of failure for critical user directories. The risk is asymmetrical: the benefit is automated backup, but the potential cost is operational disruption to the core Windows user experience. For future stability, consider using OneDrive to sync a dedicated folder structure rather than redirecting system-defined profile folders, maintaining a clearer separation between cloud storage and local system paths. This incident underscores the necessity of maintaining a robust, separate backup regimen even when using a sync service, as synchronization is not a substitute for versioned backups, and configuration errors can quickly affect primary data accessibility.