Recovery guides
Most common recoveries
Each guide covers what the error actually means, the safe order of operations, and the commands that do the work. Every one links straight back into the recovery form.
Spreadsheet
Excel: 'file format or extension is not valid'
Why Excel rejects a workbook that opened yesterday, and the non-destructive order to try: copies, Open and Repair, XML surgery, then salvage.
Document
Recover an unsaved or overwritten Word document
Where Word actually keeps autosave, temp and version copies, and how to pull an older version back without destroying the newer one.
Code or Script
Undo a git reset --hard and get your commits back
git reset --hard does not delete commits — it moves a pointer. Use reflog and fsck to find the dangling commits and restore them safely.
Code or Script
Move commits made on the wrong branch
How to move commits off main onto the feature branch they belonged to, without rewriting anything you already pushed.
Files & Folders
Repair a corrupted .zip or .rar archive
Truncated downloads, damaged central directories and partial archives — how to extract whatever is still intact.
Database
Recover a database after a half-run migration
A migration that failed halfway leaves a mixed schema. Snapshot first, then decide between point-in-time restore, manual repair, or .recover.
Files & Folders
Undo an accidental batch rename
Rebuild original filenames from embedded metadata, shell history and filesystem records after a rename script went wrong.
Photos or Media
SD card says 'format disk' — recover the photos first
Why you must never format, how to image the card read-only, and which carving tools recover JPEG/RAW/video from a damaged filesystem.
Spreadsheet
CSV opened with everything in one column
Delimiter, encoding and quoting mismatches explained, with the import settings and command-line fixes that restore proper columns.
Document
Recover a Google Doc after a bad paste or revision
Use named versions, revision history and Drive's trash to get a Google Doc back to the state before a destructive edit.
Files & Folders
Get data out of a corrupted PST or MBOX mailbox
Repair or extract messages from damaged Outlook PST/OST and Unix MBOX files without losing the original archive.
Files & Folders
Recover files after an interrupted rsync or move
Work out what actually transferred, find partial files, and finish the copy safely after an interrupted rsync or mv.