if youv'e had this problem then your not alone and many have tried the sorting the codec route to no success but here is something that apears to work.
I think that I started getting these errors after I installed Pinnacle Studio 8. Uninstalling it didn't seem to help.
I finally found a solution on www.codecguide.com/faq.htm. Their suggestion was a little scary. This is what they recommended:
Start > Run > type regedit and press enter
Navigate to: HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers
If there is an entry in there with the name DivX in it, delete it.
Navigate to: HKEY_CLASSES_ROOT\SystemFileAssociations\.avi\shellex\PropertyHandler\
Delete the value (default). It will appear as an empty value.
That didn't seem to work for me, but it helped me understand the problem. Windows was trying to read the info about the file so it could show a pop-up with info about the .mpg file. Their solution was to remove the instructions that tell windows to do the file lookup. Cool.
What actually worked for me was this:
(in regedit)
Navigate to: HKEY_CLASSES_ROOT\.mpg
click the entry named shellex
(make a backup, just in case) on the menu, choose file > export. (this creates an undo file that you can put back by double-clicking the undo file)
Delete the entry named shellex (right-click, delete)
* problem fixed *
Warning: in general, deleting stuff from the registry (especially if you don't know what you are doing) is a simple & quick way of TOTALLY WRECKING your computer. So, go slow. Deleting stuff from the registry usually makes things worse instead of making things better. However, in this situation, it actually helped without trashing my stuff. Please be careful!!!!
If you are having problems with .mpeg, .avi, etc, you may have to repeat these steps for those registry entries too. Otherwise, don't delete anything else. Close regedit and forget you ever knew about it. (for your own safety).
Pasted from <http://www.bleepingcomputer.com/forums/lofiversion/index.php/t42868.html>
give it a try, the second part has worked for me.
