Els said:
Windows XP Home's 'tell the user what not to do' system?
Just pick any file on your pc, try and change the extension. A prompt
will show saying something like "changing the extension of this file
may leave the file unusable - do you still want to change it?" with a
'yes' and a 'no' button to choose.
Renaming won't affect the contents of the file at all, and certainly
won't destroy them. The Windows warning is a reflection of the fact that
virtually all Windows applications rely on the file extension to
determine how to handle the file: how to open it, how to embed it, etc.
If you change the file extension, the risk is that Windows won't be able
to figure out on its own how to work with the file. And, it may make it
a little more difficult to open the file from within an application, as
most applications default to showing you just those files that it knows
how to handle ... as determined by the extension.
But renaming the file won't hurt the file contents. All that gets
destroyed is the old name.