Tech Tip: File Extensions for MS Windows

Support our work with a
tax deductable donation:
LINC is a project of
the National Center for Law and Economic Justice.

download this techtip in pdf format

What to do when your computer doesn't know how to open a file:
This TechTip Applies to computers running Windows

If you use email to communicate with your constituents and allies, then you've probably received an email attachment (for more information on sending and receiving email attachments see Tech Tip 5. Sometimes, you'll get an attachment that your computer doesn't know how to open.' When this happens, you're likely to see this dialog box:

The problem that your computer is having is that it can't identify which program to use to open the file. Your computer decides on which program to use based on a file's extension.' File extensions are the three-letter extension that comes after the name of a file.' The file extension tells your computer what program it needs to use to properly open the file so that you can read it.' To see file extensions, click on the Start Menu, and select Settings, then select Folder Options.' From the Folder Options dialog box, select View, and make sure that box for "Hide File Extensions for Known File Types" is unchecked.' If you open your C: drive, you'll see that the files all have a three letter extension at the end of the filename, so a Microsoft Word document called techtipnine would appear as techtipnine.doc, where .doc is the file extension.

The table below lists some common file types (the more common ones are listed first), as well as the program you need to be able to open it.

File Extension What it means Program that you need to read the file
.doc This is a Microsoft Word File Microsoft Word or another program that reads MS Word documents, i.e. some versions of WordPerfect can read Word documents. ( It is ideal if you use the same version of Word that the file was created in.) If not, then you may have problems opening the file.*
.pdf An Adobe Acrobat document Adobe Acrobat Reader (free download at www.adobe.com).
.wpd A Corel Word Perfect File WordPerfect or another program that reads Corel WordPerfect documents, i.e. some versions of Microsoft Word can read WordPerfect documents.' It is ideal if you use the same version of Word that the file was created in.' If not, then you may have problems opening the file.*
.xls A Microsoft Excel spreadsheet Again, you will ideally have the same version of Excel that was used to create the file.
.mdb A Microsoft Access database Microsoft Access or other database program that can read Access files.*
.htm or .html A web page Internet Explorer or Netscape Navigator/Communicator.
.dbf A Dbase file Most database programs can open this type of file.
.bmp A bitmap file This is the file format that Windows uses to save its icons.' It's also the file type that Paint uses to save files.' To open the files, you'll need Microsoft Paint or another graphics program.
.pub A Microsoft Publisher File Microsoft Publisher.*
.txt A plain text file Any word processor can open this file.
.rtf A rich text file Most word processors can open this file.
.gif, .jpg, .png Different types of graphics files To edit the files, you'll need a graphics program.' To view them, you can use your web browser.
.fp3, .fp4, .fp5 A File Maker Database file Depending on the number (3,4, or 5) you'll need either that version or higher of File Maker, or else a current version of another database program that can read the File Maker files.*
.pm6 An Adobe Page Maker 6 File You'll need Adobe Page Maker to open this file.
.psd, .tif A graphic file .psd is an Adobe Photoshop file, which can be read by most high-end graphics programs.' .tif is a more general high-end graphics format, which can by read by most graphic-design programs.
.exe An executable file This is a program, double clicking the file will run the program.' Be careful when opening an .exe file that you've received as an email attachment as it can be a malicious, virus-like program.' Do not open the file unless you know the person who sent it, and are expecting to receive a program from them.'
.vbs A Visual Basic Script file If you receive this type of file as an email attachment, and are not expecting to receive it, be very cautious.' .vbs files are some of the more common forms of viruses found on internet.' If you cannot confirm that you were sent this file on purpose, delete it and run your anti-virus software.
.mp3, .ram These are media files: .mp3 stands for mpeg layer 3, and is used for music, .ram is a real audio or video file, for Real Player To listen to an mp3 file, you'll need a media player.' Real Networks has a free version of their Real Player available at www.real.com, and there are a number of good mp3 players available.' Common ones include Winamp (www.winamp.com) and Music Match Jukebox (www.musicmatch.com) .
.mpeg, .mov Video files The newest version of Real Player will handle these files, as will Windows Media Player (www.microsoft.com).

*With newer software, you will usually have the option of installing file format converters that will let you read many different types of files.' The process for this usually works in this way: 1) you try to open a file that you don't have a converter for – for example, opening a Corel WordPerfect file using Microsoft Word.' 2) Word will tell you that it does not currently have the feature installed, and will ask you if you want to install it.' 3) You'll need to use your software CD to install the converter, and then you will be able to open the file.

If you find that you cannot open a file, and do not have the software necessary to open the file, you still have some options.' If you received the file as an email attachment, contact the person who sent it, and ask them if they can resend it in a format that you can read, i.e. if you cannot open a document that they saved as a MS Word file, as them to resend it as a text or rich text format file (.txt or .rtf).' If this is not possible, there are a number of programs on the market that you can use to convert files.' One that is highly recommended is Conversion Plus from Dataviz ( http://www.dataviz.com/products/conversionsplus/index.html).'