.eml usually is an email, saved from Outlook Express. You can import it again in Outlook Express. Then there might be a video as attachement.
.wmv is a windows media video indeed. It should be playable with WMP 8 or higher. Otherwise try VLC Player (free), or Irfanview (also free) as a last resort.
.ppt (assuming that is) is a Powerpoint presentation. You need MS Powerpoint, Open Office Impress (free) or the MS viewer for Powerpoint files (free from http://www.microsoft.com/downloads/details.aspx?FamilyId=428D5727-43AB-4F24-90B7-A94784AF71A4&displaylang=en for versions up to Powerpoint 2003)
And never change file extensions, or you make a mess of it.
I have a small collection of short video clips that were sent to me from friends overseas and which mean a lot to me. Unfortunately since I bought a new (and different) desktop, I can no longer view them. When I try to view them with Windows Media Player all I get is:
"The file you are attempting to play has an extension (.wmv) that does not match the file format. Playing the file may result in unexpected behavior.
Do you want the payer to try to play this content?"
If I insist and ask for playing, I get:
"Windows Media Player cannot play the file type or might not support the codec that was used to compress the file"
These messages come up with the following extensions: wmv, pptm, eml.
I cannot remember what were the original extensions used upon first save. These videos were viewable for a year before I transferred them to an external HD and then onto my new computer, an iMac with Bootcamp & Windows XP pro. I am working in the Windows environment with these videos. The Operation system (XP pro) is the very same one I had installed on my previous desktop. I have tried using Quick Time player or changing extensions, both without result.
Can someone please help? Thank you.