how to recover old files in one drive

Hello Harvinder,

Thanks for reaching out and I appreciate you sharing the details of your situation. I understand how concerning it must be to lose access to your OneDrive files especially after reinstalling Microsoft 365 and encountering a server error. It's frustrating when important documents suddenly become inaccessible and you're left unsure of what steps to take next.

The issue you're experiencing particularly the “500 Internal Server Error” typically points to a temporary server-side problem or a disruption in the sync between your device and OneDrive. This can happen after unlinking your account or reinstalling apps especially if the sync wasn’t completed properly or if the files were not fully downloaded before unlinking.

To help resolve this I recommend starting by signing in to OneDrive online using the same Microsoft account you previously used check if your files are still visible there. If they are you can download them directly or restore them from the OneDrive Recycle Bin if they were accidentally deleted. If you don’t see your files try using the “Restore your OneDrive” feature available to Microsoft 365 subscribers which allows you to roll back your OneDrive to a previous state within the last 30 days.

If the error persists across devices and browsers it may be due to a deeper server issue. In such cases clearing your browser cache, switching to incognito mode or trying a different browser may help. You can also attempt to reset OneDrive by running the command %localappdata%\Microsoft\OneDrive\onedrive.exe /reset on your PC. Additionally checking the OneDrive sync status from the taskbar and repairing the sync connection might restore access to your files.

Have you had a chance to check your OneDrive storage online or tried accessing it from a mobile device? This can help confirm whether the issue is device-specific or account-related. Also were your files marked as “available offline” before unlinking?

I hope this answer is helpful if you have further questions feel free to reply back

Regards,

Marcelo