If you accidentally delete a file in OneDrive, you can recover it from the Recycle Bin. First, sign in to portal.office.com and open OneDrive. In the left-hand menu, select "Recycle Bin" to view deleted files. Find the file you need, click on it, and select "Restore" to move it back to its original location. If the file is missing from the Recycle Bin, check the "Second-stage Recycle Bin" (for business accounts). Files are kept for 30 days (or 93 days for some business accounts). If permanently deleted, try contacting Microsoft support for further assistance.