Most commonly, the file extension ASD indicates an AutoSave file for Microsoft Word. When you're working on a document, Word automatically creates backup files in case the program crashes. Converting an ASD file may be your only chance to recover lost work. You can open an ASD file in Word and convert it to a DOC file.
Open Microsoft Word. Click the "File" menu, then click "Open."
Go to your username folder. You can find it in the drop-down menu at the top of the window.
Double-click the "AppData" sub-folder inside your user folder. Double-click the "Roaming" folder, then select the "Microsoft" folder. Open the "Word" folder.
Click the drop-down menu at the bottom of the window labeled "Files of Type," then click "All Files." Double-click the ASD file to open it.
Click the "File" menu, then click "Save As." Under "Save as Type," select the DOC file format. Select a location for the converted file, then type in a name and click "Save."
The file extension ASD may indicate another file type, such as a sample analysis file for Ableton Live. You can use the program associated with this file type to save it in a different format.