VLC HowTo/Transcode from Flash Video format
You can use ffmpeg to change .flv files to .avi files (or one of many other types of files).
If you have problems playing .flv files, changing them to .avi will probably fix the problem.
Windows
Install
Precompiled windows binaries are avaliable at:
Pick the file ffmpeg-SVN-r6708-static-gpl-win32.zip
Extract the files from the .zip and copy ffmpeg.exe to your Windows directory (Windows folder), or somewhere else in your search path.
Run
Ffmpeg.exe is command-line based, so to use it you need to open a command prompt. In the start menu pick "Run", and type
cmd.exe
into the box and press enter. This opens a cool black box with white text. It'll say something like C:\>.
At the prompt, type
cd "somewhere"
where "somewhere" is the path to the folder where you saved your files, it's probably something like
cd "c:\windows\profiles\user\Desktop\"
Then press enter. You can find out the path (location) of a file by right clicking on the file and selecting properties.
Finally type
ffmpeg -i "your_file.flv" "your_file.avi"
and press enter. This takes "your_file.flv" as the input file and spits out "your_file.avi" as an avi file. Job done (at last!)
Close the command prompt by closing the window as normal, or typing "exit".