fichiers supprimés de onedrive

You have already tried File Recovery and searched synchronized devices, so I would not suggest repeating those scans without new evidence. First establish whether this was personal OneDrive or a work/school account. Microsoft documents different recycle-bin periods: normally thirty days for personal accounts and ninety-three days for work/school accounts, unless the administrator changed retention. Check the web recycle bin for the correct account; for an organizational account, ask the administrator to investigate recovery and retention options. The full-OneDrive restore feature covers the previous thirty days and does not override permanent deletion. If the items are permanently removed from the recycle bin, Microsoft says they cannot be restored through that mechanism. Look instead for independent copies, such as offline backups, email attachments or previous exports. Avoid installing more recovery tools onto a disk that might contain recoverable local data, and do not pay for guaranteed cloud recovery claims