Windows Guide

Guide to File Types

Windows maintains a list of different file types based mainly on the file extension of the file and these are stored in the Registry. Every time you double click on a given file, Windows will know what file or program to load with that file. Not all files will open an application and these are special files used by windows or application programs as library files (DLL), data files or someother special function. These should not be opened or assigned to any program.

To view the file types of applications that are installed:

a) Enter a file type or link type in the search box at the top, for example, enter .doc, and it will display the associated application underneath, e.g. Microsoft Word.

b) In the Search apps box, enter name of the application, it will display the application, clicking on the arrow on the right will display the associated file type.s

c) Select an application from the list, and it will list all the associated file types underneath.

If the file is a known application file which can be opened then there are three ways you can allocated that file to an application:

a) Double click on the file and an Open With dialog box will appear and you can either choose a known program from the Internet or select a possible program from a list. Select the application from the list or click on Browse to choose another program not in the list. If you want it to be a permanent assignment then tick the box 'Always use the selected program to open this kind of file' (this box is unticked when a file has no extension).

b) If the file is already allocated to a program, then you can reassign it to a different program by selecting the file and pressing Shift key and pressing the right hand mouse button to bring up the pop up menu. The Open With option will appear and then you can assign the file to another program as before.

c) Select or search for the file type or program, e.g. Paint, then expand the program to view the associated file types, select the file type you want, e.g. .bmp, and a pop up window appear with a list of other programs you can associate it with e.g. Corel Paint Shop Pro.

To disassociate a file type from a program, you will have to use the Regedit tool and completely remove its entry under the HKEY_Current_User\Software\Microsoft\Windows\Currentversion\Explorer\FileExts or create a batch file and supply the extension as a parameter, as follows:

@echo off
ECHO Removing file extension %1
REG.EXE Delete HKCU\Software\Microsoft\Windows\Currentversion\Explorer\FileExts\%1 /f

Here is a short list of file types that you may come across (NB: Binary files look like garbage when viewed and should not assigned or deleted):

Protocols

CD Recording