How to Recover an ASD File. A file with the file extension of ".ASD" is an automatically-saved backup file for a Microsoft Word 2002 or 2003 document.

AutoRecover is a Word feature that automatically saves temporary backups. It can help recover unsaved Word document on Windows 10/11, but only if it was turned on before the file was lost.

There's a cool trick that can help you retrieve lost and unsaved Word documents by searching for .asd in the File Explorer under My/This PC.