Excel file shows 0 KB / zero bytes after a crash, power loss, or interrupted transfer and won't open

What's actually wrong

A 0 KB file means the directory entry exists but the contents never made it to disk — typically a crash or power loss mid-save, an interrupted copy to USB/network, or filesystem damage. Here's the honest part most repair-tool marketing skips: a file that is truly zero bytes contains nothing, and nothing can repair it. Recovery is still often possible, but it comes from other copies — AutoRecover snapshots, Windows previous versions, cloud version history, or the deleted pre-save original still sitting in freed disk space (Excel saves by writing a new file and deleting the old one).

Free fixes — try these first

1. Excel's own safety nets first: File → Open → Recent → Recover Unsaved Workbooks, and check the AutoRecover folder (File → Options → Save shows the path, typically C:\Users\you\AppData\Roaming\Microsoft\Excel\) for .xlsb/.xar snapshots.
2. Previous versions / cloud history: right-click the file → Restore previous versions (File History/shadow copies); on OneDrive, SharePoint, or Google Drive, open version history online and restore the last non-zero version.
3. Hunt the temp files: sort %temp% and the file's own folder by date-modified around the crash time, looking for ~-prefixed or .tmp files of plausible size; copy one, rename to .xlsx, and try opening it.
4. Undelete the pre-crash original: because Excel replaces the old file on save, the previous good version was 'deleted' at crash time — a free undelete tool (Recuva, PhotoRec) scanning that drive frequently finds it. Stop writing to the drive first to avoid overwriting it.
5. If it's on USB/SD: run chkdsk /f X: — interrupted writes sometimes leave the data in lost clusters that chkdsk reattaches as .CHK files; also try the copy that may still exist on the source machine.

If the free fixes fail

If Explorer shows a real size but Excel still won't open the file, the write was interrupted partway rather than lost entirely — our analyzer determines in seconds whether any sheet data survived inside and shows the honest recovery percentage; and if the file truly holds zero bytes, it tells you that immediately so you can spend your time on version history instead of on tools that can't help.