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What is this file that I cannot open?

It is quite common, in modern computing, to encounter a file that your computer does not recognise.

A file type extension is a set of characters added to the end of a file name that determines which program should open it. By default, Windows Explorer hides file name extensions, however you can make them visible.

The file type extension is the bit that comes after the document name and the dot i.e.

  • myworddocument.docx
  • anewspreadsheet.xlsx
  • mywebpage.html

You will probably recognise the extensions (above) as Microsoft Word (docx), Microsoft Excel (xlsx) and a web page (html).

Every creator of new software will usually define some proprietary objects or files and will need to create a new file type extension for it that does not clash with the naming of an existing file type. Continue reading to see how to view the file type extension, how to handle "unknown" files and how to convert one file type into another.

  • Unknown File Types and Viewing the Extension

    Recognised Files

    FileType1,

    When viewing a list of files, on your Windows or Mac computer, you will usually see a small icon (picture) next to the file name. This is the program that is associated with that file e.g. a .docx file is a Microsoft word processing file and will often have the Microsoft Word logo as its icon (or the Apple Pages icon on a Mac).

    Trying to open this file will launch your default word processing software and load up the document.

    Unrecognised Files

    FileType2,

    An unknown file type will normally have an icon that looks like a blank page. This does not always mean that your computer cannot open the file; it just means that your computer does not recognise it and may not have opened one of these files before. Unless a program, such as Word, tells your computer that it knows what this file is - your computer cannot associate it with a particular program.

    Trying to open this file will often launch a "File not recognised" dialogue window. Both Windows and Mac will offer you the option to search for a program or app to open the file, but this is not always successful.

    Viewing the File Extension

    If your computer is set to show you the file extension - you will be able to see it after the file name whenever you open a folder of files in Windows Explorer e.g.

    • afilename.docx
    • avideofilename.wmv  

    If you cannot see file extensions, then the following steps will enable this function:

    Windows 10 and 11
    • Start Windows Explorer (you can do this by opening up any folder)
    • Click the View tab at the top of the window
    • Tick the box for File name extensions

    FileType7,

    Mac OSX

    In Apple Finder, select Preferences and tick the Show all filename extensions option:

    mac_finder_preferences,

    Before and after

    Before the file type extension is visible, all you can see is the file name and an icon for any associated program. This is only useful for files that your computer already recognises:

    FileType5,

    After the file type extension is visible, you can now try to find a program that will open your "unknown" files:

    FileType6,

    In this case, I have an unknown .xfd file type. 

    Mac:

    mac_finder_extensions,

    What will open this file type?

    FileInfo.com provides a database of over 10,000 file type extensions.

    A simple search box allows you to input the letters of any file extension.

    It will then tell you all about the file and gives you a list of programs that will open it (where available) on Windows, Mac and Linux.

    In the case of my .xfd example, this is a data file that can be opened with Adobe Reader.

  • Converting Office Files

    There are circumstances when you might need to convert an office document (docx, xlsx, pptx, etc.) into a different format. This is most common when you want to make a document compatible with other programs / systems or if you want to submit some coursework as a PDF document.

    You may also come across some file types that you are not immediately familiar with such as:

    • .wps / .wks / .wdb - from the Microsoft Works software
    • .odt / .ods / .odp / .odb - open document formats from OpenOffice, LibreOffice and others
    • .pages / .key / .numbers - Apple specific formats similar to Word, PowerPoint and Excel
    • .gdoc / .gslides / .gsheets - Google Drive file formats

    Saving Microsoft Office 365 files as other formats

    In this example, we will save a Word document as a PDF (Note: although the screens look slightly different in Office365 for Mac - these steps are the same).

    From an opened Office document (Word, Excel, PowerPoint, etc.) - Select the File tab at the top left of your screen:

    OfficeConvert1,  

    From this new screen, choose Save As

    OfficeConvert2,  

    And then you will need to choose a location to save your converted document

    OfficeConvert3,  

    Finally, choose (from the Save as type drop down menu) which format you would like to save your document as and click Save.

    OfficeConvert5,  

    This will work for most objects in most Microsoft Office programs including Word, Excel, PowerPoint, Publisher, OneNote and Access.

    Please note: The Convert button, in one of the images above, will only convert your document into the latest file format associated with that program e.g. if you open an older .doc file, the Convert button will resave your file as an Office365 compatible .docx.

    Microsoft Works file formats

    Microsoft Works was a slimmed-down office suite that offered less programs and much less options than Microsoft Office.

    It was discontinued in late 2008 and it is unlikely that you will come across these file types (unless you previously studied prior to 2008).

    The main file types created by Works were:

    • .WPS (word processing)
    • .WKS (spreadsheets)
    • .WDB (database)

    Zamzar online file converter can convert the WPS and WKS files into more modern formats.

    MyDigitalLife provides a downloadable WDB converter for Windows.

    OpenDocument - file formats

    About OpenDocument Formats

    Open Document is a set of file formats that were developed in order to create a free and open set of file types that could be used by everyone. The file types currently include:

    • .odt for word processing (text) documents
    • .ods for spreadsheets
    • .odp for presentations
    • .odb for databases
    • .odg for graphics (images)
    • .odf for formulae, mathematical equations

    Support for these formats has grown to the point where most Office Suite programs can open edit and save these formats. OpenOffice, LibreOffice and others use these file formats as their default file types.

    You can open these documents in your preferred Office software and simply resave as an alternative (in the same way that you would resave a Word document as a PDF [above]).

    If you encounter any problems, Zamzar online file converter can convert all of these file types into Microsoft Office formats.

    Mac file formats

    The file formats for Apple Pages, Keynote and Numbers are not widely supported outside of the Mac OSx operating system.

    To submit assignments created in one of these programs/apps, you will need to resave them as Windows compatible formats such as the Office365 equivalents (.docx, .pptx and .xlsx) which can be done simply through the File menu.

    1. 1 With the Pages app open, select the File menu.
    2. 2 Choose Export To
    3. 3 Select either Word... or PDF...
    4. 4 The resultant file can now be submitted to Turnitin or shared with users of non-Apple devices.

    Please note: Microsoft Office 365 Professional is available for our students and staff to download on Apple Mac devices: Free Office Software

    If someone has sent you a .pages, .key or .numbers file and you are working on a non-Apple device, the easiest ways to be able to read these files are:

    1. 1 Ask the sender to resend in Microsoft Office or PDF formats or
    2. 2 Visit Zamzar online file converter and convert the files yourself. Note: the formatting of the converted file may not be exactly the same as the original, but all of the content will be there.

    Google Drive file formats

    If you are sent a link to a Google Drive document, presentation or spreadsheet, then you should be able to click the link and view the shared file in a web browser window.

    If you want to edit one of these files (either your own or one shared with you) you will need to be logged into a Google account.

    To edit one of these files offline, you will need to be using a Chromebook or download the file. The Google Drive will automatically convert files to Word, PowerPoint and Excel formats when you click the Download button.

    To submit work created in these Google formats, you will need to download or save them in the Microsoft Office formats (.docx, .pptx or .xlsx).

     

     

  • Converting Images

    It is possible that you may receive or download an image or diagram in a format that you do not recognise. This might make it difficult for you to edit or use in an assignment. It is also worth noting that some image formats, such as .BMP, can be very large files for a relatively small image.

    To get around these issues; we can easily convert images into other formats / file types using an app or program on your device or online (Note: JPEG/JPG and PNG are very widely supported and produce good quality images with a relatively small file size).

    On your device

    Windows MS Paint: How to use MS Paint (wikihow.com)

    Mac OSx: The Image Converter

    Mac OSx: How to convert image file types using Preview

    Windows / Mac OSx / Android / iOS: XNview (see below for more information)

    XNview

    XNview is an easy-to-use photo viewer, organiser and converter for use on your own computer or pendrive. XNview is FREE software that can view over 500 image types:

    In addition to this - XNview can then re-save those viewed images as one of 70 different file formats.  

    XNview (FREE download)

    If you want to download and use XNview on your own computer; visit the download page here:

    http://www.xnview.com/en/xnview/#downloads

    And following the installation instructions.

    Note: The XNview Min. Setup option will be sufficient for most users.

    XNview Portable (FREE download for Windows only)

    If you want to use XNview on more than one computer and/or on restricted computers (such as those at University); you can download and install XNview Portable on a PenDrive. The PortableApps version can be run, from your pendrive, on almost any Windows PC.

    Download XNview Portable (ignore any download buttons except the one that gives a version number and file size)

    XNview – Converting Files

    XNview will offer to catalogue all of the images on your computer – this makes it easier to find them if you want to view / convert / edit them.

    To do a quick file conversion on an image:

    • Simply open / run XNview
    • Select the File menu (top left)
    • Select Open and browse for an image file
    • With your image open:
      • Select the File menu
      • Select Save as…
      • Choose a suitable file format (.jpg .jpeg is most common)
      • Browse for a location to resave your file

     ImageConvert2,

    Zamzar and Image Conversion

    Zamzar and Image Conversion

    This is our recommended solution for students / staff who are not familiar with good quality image editing software. Zamzar is a FREE online service that can convert a wide range of file types into many others. It can convert images, office files, audio and more.

    How to convert a file with Zamzar

    1. Visit http://www.zamzar.com/ and you will see the content area (shown here):

    ImageConvert3,  

    2. Choose Files... to browse your computer for your image to convert.

    3. Select a suitable file type from the formats drop-down menu (.jpg or .png are usually safest for most uses):

    ImageConvert4,  

    4. Enter your email address (this is used to send you a link to your converted file).

    5. Click on the Convert button. In a few moments (sometimes longer at busier times) you will receive an email with a link to your converted file.

    6. Follow the link and download your newly converted image.

    Please Note: If your converted image is presented to you on screen (this happens in some browsers) - simply right-click the image and select to "Save image as…". You will now be able to choose a location to save your newly converted image.

    Other online image converters include:

    Image Converter | CloudConvert

    Free online image converter (online-convert.com)

    Image Converter (Online & Free) — Convertio

  • Converting Audio

    Audio recordings from Digital Voice Recorders, Mobile Phones and downloads from the internet; can be in many different formats. Some are more widely supported than others and you may need to convert an audio file into something that your tutors can hear and/or assess.

    Converting Audio Files, from one type to another, is fairly simple to complete.

    The following two options will allow you to convert most common audio file types into something more usable. These can be completed using University computers or your own device.

    Audacity – Converting Audio Files

    At its simplest level - Audacity can import and export WAV, AIFF, AU, FLAC and Ogg Vorbis files. By downloading the additional libmad plugin - Audacity can import MP2 and MP3 files. And by adding the free Lame Encoder - you can use Audacity to create MP3 files.

    See our dedicated Working With Audio page for more information about working with MP3 files.

    Converting Audio with Audacity

    1. Right-click on an audio file and select to "Open with…" > Audacity.

    2. Optionally; after you open the file - you can edit it.

    3. Select the File menu (top left).

    4. Select to Export your audio file.

    5. Choose a file type for your converted file (MP3 is usually the most usable and compatible).

    AudioConvert01, screenshot of an audio converter 

    6. Choose a location to save your new file.

    Note: DO NOT choose any of the SAVE options in the File Menu! This will save your file as an Audacity Project file. These can only be opened and played in Audacity.

    Zamzar – Converting Audio Files

    Zamzar is a FREE online service that can convert a wide range of file types into many others. It can convert images, office files, audio and more.

    For audio/music files; Zamzar can view and convert the following file types:

    • 3ga - 3GA Multimedia File
    • aac - Advanced Audio Coding File
    • ac3 - AC3 Audio File
    • flac - Free Lossless Audio Codec
    • m4a - Compressed video file
    • m4r - iPhone Ringtone File
    • mp3 - Compressed audio file
    • ogg - Ogg Vorbis Compressed Audio File
    • ra - RealMedia Streaming Media
    • ram - RealMedia Metafile
    • wav - Windows audio file
    • wma - Windows Media Audio

    Although Zamzar can convert most of these file types into any other on the list (with some exceptions); it is usually safest to convert your files to MP3 - which is currently most compatible with media players and other software.

    How to convert a file with Zamzar

    1. Visit http://www.zamzar.com/ and you will see the content area (shown here):

    ImageConvert3,

    2. Choose your audio file to convert (this will allow you to browse for a sound file on your computer).

    3. Select a suitable file type from the formats drop-down menu (.mp3 is usually safest for most uses):

    AudioConvert02, screenshot of an audio converter

    4. Enter your email address (this is used to send you a link to your converted file).

    5. Click on the Convert button.

    In a few minutes (sometimes longer at busier times) you will receive an email with a link to your converted file. Follow the link and download your new MP3 or WMV audio file.

  • Converting Video

    Converting Video Files, from one type to another, has previously been an overly complicated process, but is often required because the device you used to record your video has created files that will not play or edit on either your computer or on those at University.

    Video File conversion is now a much simpler process.

    Listed on this page are a number of ways to complete this; depending on the type of file you want to convert and whether or not you are using a University computer or your own.

    • Windows Movie Maker (most University computers)
    • Premiere Elements (Lancaster Media Editing Suite and Brampton Rd)
    • Zamzar.com (Online conversions - any computer)

    Movie Maker - Converting Files

    Windows Movie Maker is available for all Windows computers and is installed on University PCs.

    Make sure that your video is in a format that Movie Maker (Live Essentials version) can read [.wmv .mov .avi .asf .mp4 and some .mpeg].

    1. Open your video file in Movie Maker

    File > New project > Drag video files onto the Movie Maker screen

    2. Select the File menu (shown here)

     MovieMaker01,

    3. Select Save movie

    4. Select For computer

    (There are many other "Save" options at this step. You might want to save For high definition display if you think your work may be put on DVD and shown on a large screen, but the file size will be much larger.)

    A window will pop up - asking you to:

    5. Name your converted video.

    6. Choose a saving format [.mp4 or .wmv] Both of these formats are widely supported. The MP4 is often better quality.

    Premiere Elements - Converting Files

    Adobe Premiere Elelments is available in the Lancaster Media Editing Suite (ground floor of the Donald Coggan building) and at Brampton Rd.

    It is a comprehensive video editing program that will accept the following video file formats:

    3GPP (.3gp, .3g2) 
    Audio Video Interleave (.avi) *
    H.264 (.mp4) 
    H.264-encoded QuickTime (.mov, .mp4) 
    MPEG-1 (.mpeg) 
    MPEG-2 (.mpg) 
    MPEG-2 Transport Stream (.m2t)
    QuickTime (.mov) 
    Video Object (DVD video) (.vob) 
    Windows Media (.wmv) 

    Import Video File(s) into Premiere Elements

    Video Tutorial: Import videos and other media

    Share a movie for playback on a personal computer

    The video you imported / edited is not available as an independent video file until you export, or share, it to a video format.

    The Share option is the easiest to use and allows you to share your video to your computer (not perfect phrasing, but sharing to your computer just means that you are saving a copy).

    After sharing, you can play it back on your computer, in other media player or editing programs, and move it to other computers. MPEG and MPEG2 presets are suitable for AVCHD-quality export.

    • In the Publish and Share panel (top right) click the Computer button.
    • Choose a format from the list at the top of the PC view. H.264 (.mp4) and MPEG-2 (.mpg) are usually the most compatible formats to use.
    • Specify a preset, filename, and location for saving the file.
    • (Optional) Click Advanced and specify options as desired.

    The following video tutorial shows some options - after 5mins 23secs you are shown sharing to computer.

    Share your video using Premiere Elements 

    Zamzar - Converting Files

    Zamzar is a FREE online service that can convert a wide range of file types into many others. It can convert images, office files, video and more.

    For video files; Zamzar can view and convert the following file types:

    • 3gp - 3GPP Multimedia File
    • asf - Advanced Streaming Format
    • avi - Windows video file
    • flv - Flash video
    • ipad - MPEG-4 (H264) Video File
    • mkv - Matroska Multimedia Container
    • mod - Hard disk camera movie
    • mov - Apple QuickTime Movie
    • mp4 - MPEG-4 Video File
    • mpg - Moving Picture Experts Group File
    • ogg - Ogg Vorbis Compressed Audio File
    • vob - Video Object File
    • webm - Multimedia Container Format
    • wmv - Windows Media Video

    Although Zamzar can view and convert these file types; it is usually safest to convert your files to either MP4, MPG, AVI or WMV - which are currently most compatible with media players and other software. It is also worth noting that Zamzar can convert your video file into Audio Only (extract the audio) by selecting to convert into an Audio Only format such as MP3 or WAV.  

    [The FREE version of Zamzar limits your file to a size of 100mb. For larger files - please see the other options on this page]  

    How to convert a file with Zamzar

    1. Visit http://www.zamzar.com/ and you will see the content area (shown here):

    ImageConvert3,

    2. Choose your video file to convert (this will allow you to browse for a movie file on your computer).

    3. Select a suitable file type from the formats drop-down menu (.mpg .avi or .wmv are usually safest for most uses):

    VideoConvert1,  

    4. Enter your email address (this is used to send you a link to your converted file).

    5. Click on the Convert button.

    In a few minutes (sometimes longer at busier times or for larger files) you will receive an email with a link to your converted file. Follow the link and download your new video file.

  • Converting Video (.MOD File Type)

    Camcorders such as the Canon FS11 (used on Health Faculty courses) use a .MOD extension to save their video files. This is very frustrating for a number or reasons.

    • The first reason being you cannot easily read .MOD files in Windows Media Player or many other top tier video applications.
    • The second reason is that users also have a horrible time trying to get their videos converted into DVD format. Most DVD burning applications do not know what to do with a .MOD file.

    Making your .MOD files usable (Illustrated Guide)

    The funny part, of this, is that the MOD file format is actually just a renamed MPEG2. You do NOT need any fancy video converter to change your MOD files into something usable!

    Karl L. Gechlik has written an excellent (and simple) illustrated article, for MakeUseOf.com, that shows you the steps to change .MOD to .MPG instantly:

    Making your .MOD files usable (Short Version)

    All you need to do is rename your video file extension!

    Change your original file MyVideoFile.MOD to MyVideoFile.MPG - the extension can be either uppercase (.MOD / .MPG) or lowercase (.mod / .mpg) as your computer does not mind which you use.

    This method will work for most users – on most computers.

    Play, Share, Edit your Video

    Your .MOD video file is now an MPEG video and can be played in Windows Media player. You can import it into Windows Movie Maker and make edits. You can put it on a CD or Pendrive (or even upload to YouTube) for sharing.

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