I am not able to play .avi files, what can I do?
If the problem only occurs with some .avi files, then those files are probably (partially) broken. Either use a tool that can fix the files or use a different AVI splitter: If you use Media Player Classic then enable the internal AVI splitter. To access these options: start Media Player Classic and click on View in the top menu, then click on Options… (the last item) and then click on Internal Filters. If you use another player, then install Gabest AVI splitter, which is a standalone version of the internal one in MPC. This splitter is able to handle most broken .avi files. If you are not able to play any .avi files at all, then the AVI source filter of Windows is probably broken. You can fix it by doing the following: Click on Start, then click on Run and type regsvr32 quartz.dll and press enter.