IMM4 Codec needed?

I've been sent some security CCTV footage on an .avi file to view, but VLC media player is giving an error which seems to say that a particular codec is needed. WMP won't play it either, and seems to regard it as music, if I'm understanding correctly. Anyway, I'm very reluctant to go looking for some potentially dodgy codec, and would welcome any advice, if possible. Many thanks. Here's the VLC error:

 

looks like some propitiatory codec. see
http://forum.videolan.org/viewtopic.php?f=7&t=41968&start=0

and possibly works on Linux
http://askubuntu.com/questions/71622/is-it-possible-to-play-imm4-codec-videos

 

Thank you Cudni So if I install the codec in 1st post it should play on WMP, yes? Sorry, don't know anything about codecs, thanks again
Unfortunately, it won't download for me. Connection keeps timing out. Not to worry...back to the 'drawing-board'.

 

I've mistrust of unknown .exe in general and especially so of ones claiming to be codecs

 

Yes indeed!! Hence my reluctance. They'll have to burn it to disc or something for me. Thanks again.