DEF files may be module definitions created during software development whilst creating a DLL. It might also be a spreadsheet and database file created by the SmartWare II database software. It is also used by the M.U.G.E.N. video game to store game data.
Open DEF File on Windows OS
- Look for an DEF file you need to open in Windows Explorer and double-click on it
- If the file doesn’t open automatically and you see a “Windows can’t open a file” message then you should search for a program which can open DEF file
- If you have a program which can open DEF file installed on your computer then launch that program and select “File” and then “Open” or similar options from its menu to open the DEF file
- If you don’t have the program installed then you need to try searching for “DEF wiki”, “how to open DEF file” in the search engine.
- Once you find the application, install it on your computer
- After the program is installed double-click on the DEF file to open it
File extensions are used by Windows operating system to specify what kind of information is stored in the file. Every file in Windows OS needs to have file extension and file extensions are used by Windows to determine which application it should use to open the file. Every application installed on Windows OS places information about which extensions it could open into the Windows registry and Windows uses this information to determine which application it should launch when user double-clicks on the file. If application which can open DEF file is not installed, then Windows will show ‘Windows can’t open DEF file’ message and buttons to either select an application on the computer which can open the file or to search the web for the application which can open DEF file.