Whenever I download a video file from my digital camera or email the video is almost completely black. However, I am able to open the video in IrfanView but it only shows in a 75 x 75mm box – if I try to bring the video to full screen it goes black again. Do I need to re-download the videos? The computer is running Windows XP.

Problems relating to video playback are always tricky to solve, since there are several factors that could be causing the problem. It is unlikely that re-downloading the videos will fix the problem, because it seems to happen regardless of which videos you download so it is unlikely to be due to the videos being corrupt themselves but instead something wrong on your computer with the video playback. A common cause of video playback issues relates to the wrong codec (compressor/decompressor or coder/decoder) being installed on the computer. Videos are encoded with a particular codec, specifying the format of the video. To playback videos the correct decompressor/decoder needs to be installed on the computer. A correct decoder is likely already installed on your computer, since IrfanView can playback the video, although there could be something wrong as it can only playback at the very small size. Generally I recommend VLC Media Player (www.videolan.org/vlc) as this has almost every imaginable codec built into the program so it can playback almost any type of video. Download and install VLC and then check whether you are able to playback the videos through this utility. If so, then your best option is to just use VLC to playback the videos since it has the codecs already installed and will save you having to track down the various codecs and install them on the computer manually.

However, if you find that VLC cannot play back the video correctly then this does not seem to be a codec problem since otherwise (barring all your videos being in a very esoteric format, which is unlikely) VLC would have been able to play the videos correctly. In this situation the next most likely culprit are the video or graphics drivers on your computer. I have seen old or outdated graphics card drivers causing issues with playback of videos and other graphic intensive applications on the computer. You should visit the website of the manufacturer of your computer graphics card and check whether an updated driver is available. If you are unsure about the manufacturer of the graphics card, go to the “Start” menu > “Control Panel” and open the “System” control panel (you may need to first select the “Performance and Maintenance” category if the control panel is displaying in category mode). In the System Properties window that appears, click “Hardware” and then the “Device Manager” button. The Device Manager window will appear showing all of the devices which are installed in the computer. Expand the “Display adapters” category and you should see the name of the graphics card installed in the computer. It is now a matter of finding the website of the manufacturer, inputting the details (such as make and model) of the graphics card, and then downloading and installing the latest drivers. However, make sure that you only download drivers from the actual manufacturer’s website, and not an unofficial third-party website. Often I have seen users downloading drivers from unofficial websites and these packages can often be infected with viruses and other malware. Only download and install items from the official website – for example, if the manufacturer is NVIDIA then only download and install items from www.nvidia.com .