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Computer Repair Vancouver Overview: File Extensions

Posted by on 17 Aug 2010 | Tagged as: default programs, file associations, file extensions, file formats

It is considered common computer knowledge that every file within an operating system (Windows, Mac OSX …) has a name. Just take a look through your computer right now. All of your text documents have a name. All of your music files have a name. All of your pictures have a name. Even the files created by someone else (either your friends or the computer itself) all have names. As is evident, the file name is a vitally important part of any modern day operating system: Windows, OSX, or Linux. Unfortunately, having spent a considerable amount of time helping novice users, Computer Repair Vancouver is well aware that most people do not fully understand the role of the file name.

The file name, itself, has two important roles. First off, as most computer users know, it allows you to label your data so that information is easier to find. However, just as importantly, it allows your computer to keep track of what type of file it is and with which programs it should be associated with.

Let’s go through a simple example to show you what we mean. Open up a program (Computer Repair Vancouver recommends something common like Microsoft Word or Adobe Reader) and select the “File” menu (generally located in the top left corner of the window). Now choose “Save As”, and take a look through all the options you have when saving a file onto your computer. One option should read: “file name”; this is the description you want to associate with this document. A second option should read: “Save as type”; it is this option which tells you what type of file it will be, as well as (implicitly) what programs it should be associated with.

Say, for example, we here at Computer Repair Vancouver open up Microsoft Word and choose File ==> Save As. We set the file name to “test” and then make sure the type is set to “WordDocument(*.doc)”. Finally, we hit the save button. We have just told our computer that we want a file named “test” with the file extension “.doc”. In other words, we want our PC to know that this is a Word Document that should be associated with Microsoft Word. If, a minute ago, we had set the file type to “Plain Text(*.txt)” and saved the file we would have been telling our PC that we want this to be a simple Plain Text file associated with Notepad or WordPad (two free Windows applications that can deal with Plain Text files). Notice how the file type (also known as the file extension) determines what type of file it will be as well as what program it should be associated with. The file extension DOC means the file is a Microsoft Word document which should be associated with Microsoft Word.

Here is a short list of common file extensions and their default associated programs

  • DOC — Microsoft Word
  • XLS — Microsoft Excel
  • PPT — Microsoft PowerPoint
  • PDF — Adobe Reader
  • JPEG — Default graphics program
  • HTML – Default web page program

Notice above, how we stated that some file extensions are opened with some “default” program. This is because while file extensions are static (DOC always means Microsoft Word File), their associated program can be changed. For example, you can choose whether you want a DOC file to be associated with Microsoft Word or Open Office (a free alternative to Microsoft Office which can open many types of files).

Before we go any further we are going to talk about how to show or hide file extensions within Windows.

Computer Repair Vancouver’s guide to showing/hiding file’s extensions

1a) For Windows XP:
Open up My Computer, choose the “Tools” menu item then select “Folder Options …”.

1b) For Windows 7:
Open up My Computer, select the “Organize” menu then choose “Folder and search options”.

2) For Windows XP and 7:
Click on the “View” tab then scroll down until you find the option “Hide extensions for known file types”. If you want to hide file extensions then select his checkbox and click on the “Apply” button. If you want to show file extensions then unselect this checkbox and click on the “Apply” button. For right now, make sure that this checkbox is unselected. To verify that everything is working, go to your desktop and click on any file (don’t choose a folder though). You should notice three segments: the name of the file, a dot, and a file extension. For example, you may see something like TechnicalSupport.pdf or VancouverScenery.jpeg. The most important thing to note is that pdf or jpeg tells you what type of file each is as well as, implicitly, what program this file should be associated with

Computer Repair Vancouver’s guide to changing program associations

Let’s say that by default the DOC file extension is associated with Microsoft Word (which is likely the case). How would you change it so that by default, when you double click on a DOC file, it opens in Open Office instead? To do this you have to change the default associated program.

1a) For Windows XP:
Open up My Computer, choose the “Tools” menu item then select “Folder Options …”. Click on the “File Types” tab which should show you a long list of file extensions and associated programs. Since we want to change the associated program for DOC scroll down until you see DOC and click on that particular row. Finally, hit the “Change: button and select the program you would like to open DOC files with (in our case choose Open Office – this will only be an option if Open Office is currently installed).

1b) For Windows 7:
Click on the circular Windows button located in the screens bottom left corner and select “Control Panel”. Open up My Computer, select the “Organize” menu then choose “Folder and search options”. From the Control Panel select “Default Programs” and then choose “Associate a file type or protocol with a program”. Scroll down the left column until you come across the particular file extension you are interested in (.doc for us), select the row, and choose “Change program”. Finally, click on Open Office (assuming it has been installed on your computer).

In conclusion, file extensions are a common feature of nearly every modern day operating system. Although they may be hidden from you, the user, they still exist in the background helping your workstation determine what type of files exist as well as which programs, by default, should open them. The nice thing about modern operating systems is that associations between file extensions and their default programs are modifiable which allows you to take some control over your user experience.

That is all until next time when Computer Repair Vancouver will take a look at a fairly new, and oftentimes confusing file extension: DOCX.

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