The Windows OS uses extensions to decide what program you need to open a particular data file. This relationship between an extension and a program is called association.

In File Explorer select Tools/Folder Options/File Types and scroll in the resulting dialog box to see the associations set up on the PC your are using.

File associations are a configuration issue. This means you can configure your PC to behave differently than the next person's. In the student labs at UNBC you may not be given permission to view the File Types dialog box because of the risk involved in letting users accidentally or on purpose re-configure file associations, thereby changing the behavior of the Operating System and perhaps frustrating fellow users.

The example shown is for the JPEG extension. On the Windows Installation where this picture was taken, the JPEG extension is associated with the program VuePrint.

This association can be change by clicking on Change... and browsing for a new program in the resulting list of programs. It is up to you, the user, to pick a program that will be able to read files of the JPEG data type, if you do this.

 

To find out what program is associated with a particular file, either on your desktop or in File Manager, display the properties of the file as follows: (works regardless of whether you can access the File Types dialog box illustrated above)

1. Right click on the file you want to inspect and select Properties from the resulting context menu.
   
   
   
   
2. This will bring up a window similar to the one depicted below. The part that shows the file's association is highlighted. In this case, the associated program is Notepad.
   
   

   This dialog box reveals that the .txt extension designates a file of type Text Document and should be opened with the application program Notepad