Firstly thanks for all the help received.............I have solved it now without toolbars, search engines and some of the older posts on this would need you to have a degree in computer science to follow....and still dont work!
The solution for someone like me is
http://www.afreecodec.com/963/sp44-codec-sp40---sp47-usbav170/download/
Thanks 
Guys, this may be an old topic......I had some really old video i converted to digital using an adaptec videoh thingy years ago. I cant find it but have the avi files but they wont play without this codec. Now I’ve tried all the fantastic sites on google that swear they have it and i even downloaded all the shitty toolbars, search bars in the attempt to get it but to no avail! I have more toolbars now than application ffs! I installed GOM and contrary to what they say it did go off to find the codec and put me on to one of the “download our toolbar sites and you can have it” only to redo that but still no codec. The stuff I have is over 20years old and I would hate to lose it so before I lose it can any of you guys please help, btw I’ve tried both mac and pc.