Windows File Extensions
Posted by Jason Poitras on 23 November 2006 07:15 PM
When you are in the Windows My Computer or Explorer program, you would think that you can see everything known about a file. Well, this is not always the case.If your version of Windows is not setup correctly, some critical information may be hidden on you.When you open up My Computer and go to the desired folder (on your hard drive, floppy disk or CD, etc.), you may not be able to see the 3 letter file extension or other details on each file in your folder or the information may not be what you expect.The first thing you need to set, to help you see everything, is the Views setting.
This can be set from an icon near the top of the program,
- or from the View menu
We would suggest picking on DETAILS, to be able to see everything about the file.At this point you will see the following information in My Computer.
The following information is displayed with the detail option set:
Name: The name of the file and best guess at the icon related to the program that can open it (based upon the last installed program using the 3 letter file extension).
Size: How big the file is. Helps determine if a file will fit on a floppy disk or can be emailed.
Type: What program Windows thinks is to be used when working with that file.
Date Modified: The last time this file was modified.If you notice in the above picture not all of the file names show the 3 letter extension. This is due to another setting in My Computer that needs to be changed to be able to see them.Go to the Tools menu and pick on Folder Options (Some older versions of Windows may have this command under a different menu)
Pick on the View Tab when the dialog comes up on screen to be able to see the options that can be changed. * NOTE* Be careful in here, do not start changing everything without fully understanding what it is you are changing.
The one item you can change to help you is the item marked ‚¬Å“Hide extensions for known file types. If you have a check mark there, pick on it to remove the check mark
Now pick on APPLY and OK to return to the main My Computer dialog. Now the 3 letter extensions will be displayed on all of the files.You only need to set this once and it will remain this way forever, on this computer.
So how does this help you? If you need to confirm the program that can open a file, you need to know what the file type is. The problem is that Windows, when displaying the TYPE field (and the icon beside the file NAME), only knows the last program installed that relates to the 3 letter file extension. So it may tell you that the DWG file is for AutoCAD when you in fact created the file from MSCAD. Or it may say it is for MSCAD when in fact it was created by AutoCAD. It depends upon which program (MSCAD or AutoCAD) was installed last on that computer and not necessarily the program that created the file.
Many programs can use the same file extensions but Windows is only smart enough to show the last installed program, that uses that extension, in the TYPE field (it uses this same information to show the icon in the NAME field). This can be misleading at best. So when you can see the 3 letter extension, you can manually confirm that your program can work with that file type (no matter what Windows thinks is the program to use).
Seeing the 3 letter file extension is also very important if you need to rename a file. Example: you may need to rename the BAK file (backup drawing file) to DWG (working drawing file) to be able to open it in MSCAD2005. If you can‚¬„¢t see the 3 letter file extension, then you can‚¬„¢t change it.
So renaming the file would not work as expected.So what it boils down to is the Icon and the file TYPE are helpful in some cases, but you can not rely on them to be sure that the correct program will be shown that can work with the files. The 3 letter file extension is the most important piece of information to confirm if the file can be worked with by any program.
Glen W. Cameron, C.E.T.