Beginners’ Column

By Merle Nicholson, President, Tampa PC Users Group

Do you know how to "run" a program? Lets say, for instance, you are on the Internet and download a program, maybe the Adobe Acrobat Reader from the link on the club web site. You’re asked to "Open" it or "Save this program to disk". If you (rightly) select "Save to disk", it brings up a Directory box, and you press Open. What do you do with it after you have it? If you can’t answer that question, read on. We have the right stuff here for you - I hope.

Let’s start with a quick tutorial on file names. A good example of a file will be C:\Downloads\ar32e301.exe. The C: part of the name is the drive letter, the \Downloads\ part is the Path, the ar32e301 is the name and .exe is called the extension, or in Windows terminology, the file type. The extension is what I really need to tell you about. The file type for the extension part ".exe" is program or application. The terms program and application are somewhat interchangeable. In a strict sense, a program can be a part of an application, because you can apply the term application to Microsoft Office, which is a suite of programs. But if you use Windows Explorer (you do, don’t you?) and show Details (under view, details), look to the right of any file with .exe and in the Type column, it will say Application. While you’re in Windows Explorer if you were to double-click (DON’T ! ) on an application, it will "run" the application. There are several ways to run an application and I’ll get to that and what it means, but I’ll continue first with Types and how Types relates to the extension.

In a broad sense, the file type - the three letters at the end following the dot - determines what the file is used for. We know that if you use Word and save a letter called MyLetter, Word will add the ".doc" extension to the name, and there’s a very good reason for this. If you were to double-click on a document file with the name Myletter.doc, what happens? Microsoft Word starts up and loads the file automatically. That’s because when you installed Word, the installation program registered the extension .doc in the System Registry as belonging to Word and from that time on, .doc "belongs" to word, just as .wpd belongs to Corel WordPerfect and .txt belongs to Notepad and .bmp belongs to Paint. You can mis-name a file easily to something that the operating system doesn’t have an association for and mess things up. Let’s say in Notepad you type some characters and then save-as and type in "Mystuff.bmp" for the name and you really enclose the name in quotes. The file gets saved as mystuff.bmp. If you didn’t enclose it in quotes, Notepad would have saved it as mystuff.bmp.txt ! But you did and now we have a file that is most certainly not a graphic file. If you were to double-click on it, Paint will start and then error out and tell you that it cannot read the file mystuff.bmp. The lesson to be learned here is: Always make sure that all files are saved with a three letter extension ! It was very common usage back in the DOS days to name a file MYBOSS.MEM (for a memo to my boss) or something like that. In windows you can’t do that any longer. Actually you can do things like this, but it just complicates your life and doesn’t accomplish anything.

What’s all this leading to? Well the operating system has reserved many three-letter extensions for specific purposes, and .exe is reserved for an application. So if you were to double-click on it, or create a shortcut from it and double-click on that (again DON’T), Windows will know what to do with it, just as it does for Word or Paint. And this is a good place to break. We’ll continue next month with running files. u