Guide to Windows File Extensions

Windows file extensions are the key to deciphering which software can successfully open and manipulate different types of files. If you run across an unusual file extension, you'll need to tell your computer how to open it in order to utilize it properly.

Choosing Software to Open Files
When you attempt to open a file that Windows doesn't have associated with a specific piece of software, you'll be prompted to select the software to use to open the file. In some cases, you may know what the file type is, and you can select the appropriate software. In other cases, you may need to download software or try several different programs before you get the one you need. Take the guesswork out of opening Windows software by familiarizing yourself with these popular Windows file extensions and their corresponding programs.

Media File Extensions
Media file extensions vary depending on whether you're using proprietary software, but Windows media file extensions include

.wmv
.wma
.wvx
.wax
.asf
.asx
.wms
.wmz
.wmd

Other popular media file extensions include:

.mp3
.mp4
.mpeg
.avi

Windows Media Center can open these file types, but you can also use other media programs to manage files with these extensions. If you have other media file extensions, you may need proprietary software to manage them.

Productivity File Extensions for Office
Microsoft Office is the most popular productivity software, so familiarizing yourself with Microsoft Office file extensions can enable you to spot these files when you see them:

.doc is a Microsoft Word file extension
.xls is a Microsoft Excel file extension
.pub is a Microsoft Publisher file extension
.ppt is a Microsoft Power Point file extension

Microsoft Office 2007 file extensions have an x at the end; i.e., .docx is a Microsoft Office 2007 file type. If you have an older version of Microsoft Office, you can still access these newer file types after downloading a patch from Microsoft to convert the files.

Photo File Extensions
Photo files have a lot of extensions, and not all photo programs can open all photo types. A few of the most popular photo file types that you can open with practically any photo software include:

.bmp
.gif
.jpg
.tif
.raw

Many photo editing programs use proprietary file extensions, so if you're not sure about a photo file extension, it may have come from a custom program.

Look for Information Online About Unfamiliar Extensions
If you run across a Windows file extension you simply don't know and cannot decide which program to use to open the file, try looking online for more information about the extension. FILExt is a great resource that enables you to type the extension and run a search, which reveals valuable details about what type of extension it is and what program is associated with it. If you run into a file extension you simply can't place, consult FILExt at: http://filext.com/, or run a Web search for details.