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Download a free copy of IrfanView 4.10 setup from the website,
http://www.irfanview.net.
Double click the setup file to run it, and follow the instructions to indicate the directory where it will be installed.
After two initial screens, you will come across a third screen with a caption on the top stating “Do you want to associate extensions with IrfanView? (optional")”. Right below the caption you will find a window pane displaying a list of small checkboxes followed by various image and video file extensions and their full names.

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Choose any or all the image formats that you would like to open with IrfanView after it is installed. Remember, choosing the format right now will make IrfanView the default application for opening that particular image format, although you can change it whenever you wish to do so.
Click “Next”, and follow further instructions to install the application upon your Windows XP based PC.
The image formats selected by you at the time of installation have now been associated with IrfanView 4.10, which becomes evident by all those image files being displayed by IrfanView's icon.