Click the link below to see the topic discussed at the beginners class on 04/04/2012
A file extension is commonly used to give information about the way data might be stored in the file.
You will see the extension separated by a . (dot) at the end of your file name, for example:-
Address list.doc or Xmas list.docx
Perhaps you downloaded a file from a website and could not gain access to the file.
Instead you got a message saying ‘windows cannot open this file’.
If you cannot open a file it may be because you don’t have a program that is capable of opening that type of file.
Often it is the software type that is needed rather than a particular software program. For example a .txt file extension would mean that you need a text editor, but it does not necessarily have to be notepad. A .doc file can be opened by most word processors and the same goes for a .jpg file which can be opened by most of your graphic viewers.