Class not registered *new*

"The file you are attempting to play has an extension that does not
match the file format.
Do you want the player to try to play the file? YES

Class not registered. Web help gives: error message 80040154 "

OK so now you know what error message I'm getting.

Here are the details.
Win 98 SE. Media Player 9.00.00.3250 with all the latest codecs,
directx etc.
My USB external 80G hd became unrecognizable to my system.
My system only recognizes 10G now and can't see any files on the drive.

I used recover4all recovery software. It recovered all of the lost
files. I saved them to my hard drive and later to CDs. When I try to
open any of these files I get the above error messages.

Let me make myself clear. Windows Media Player works with all of my
other files (mp3, wmv, avi etc.). It just can't open these 'recovered'
files. The files are named correctly and are the correct file size.
Everything looks fine except I can't open them.

Please help me out of this dilemma. Thanks!