ftype:tldr:39bb4

The ftype command is a Windows command prompt command used to display or modify the default file type associations on a Windows system.

This command allows you to view and manipulate the file type associations, which determine which program should be used to open a specific file type when double-clicked.

When used without any parameters, the ftype command displays a list of file types and their associated programs. Each file type is assigned a unique key, and the associated program is shown.

For example:

C:\> ftype txtfile
txtfile=%SystemRoot%\system32\NOTEPAD.EXE %1

In this example, txtfile is the key representing the file type for text files, and the associated program is Notepad.

You can also use the ftype command to change or create new file type associations. To change the association, you would use the following syntax:

ftype [fileType]=[programExecutable] %1

For example, to change the association for text files to open with WordPad, you would run:

ftype txtfile=%SystemRoot%\system32\write.exe %1

Now, when you double-click a text file, it will open in WordPad instead of Notepad.

It is worth noting that modifying file type associations requires administrative privileges, so you might need to run the command prompt as an administrator to make changes.