AVI is a generic term for several formats (for example - DIVX and XVid in addition to DVD AVI) ). What kind of AVI files are you trying to play?

How did you remove the trial copy? Before or after you installed the purchased program? Did you have your antivirus enabled during the install? When you removed the trial version, you may have removed or corrupted the codec needed to play the type of files you have.

Using the free "GSpot" codec checker, what does it say about the codecs Are the right one installed? .
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BoilerPlate: To posters who ask for help -- it is nice to thank the volunteers who try to answer your questions !
Anything I post unless stated with a reference is my personal opinion.

Stevek,

Thanks for the reply.

The removal of the trial copy occurred automatically during the installation of the paid version.

It seemed to me that the correct codecs must have been installed, at least initially, as the files played OK with the trial version. Your suggestion that perhaps the codecs had been removed or corrupted during the removal of the trial version sounded more like the problem.

So I uninstalled the paid version using Windows Uninstall Program. I then re-installed the trial version.

I then uninstalled the trial version using Windows Uninstall Program, and re-installed the paid version. It works! (at least for now!)

Thanks

Robert

Great news.

Sometimes things like that happen like that for no good reason. .
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BoilerPlate: To posters who ask for help -- it is nice to thank the volunteers who try to answer your questions !
Anything I post unless stated with a reference is my personal opinion.