First off i assume your preview doesn't work either. I had the same issue on my win8 x64 pro + MC machine as well. Get yourself Shark007 32/64 bit tools. Here's what i did. I went to the mpeg/dvd tab and told it to use powerdvd12and or ffdshow for dvd/mpeg playback. Logoff you don't have reboot entirely. You should notice the preview is working and should run. Its not the best solution i have found as every once in a while it pauses. I have to click pause and resume then it starts working again. Or if i have a window open i can also do fullscreen back to window to get the same effect of it working again. If i don't force the powerdvd12 codec it says it cant find the codec for me as well wich is bs. I even found the file in system32! I know its there. Anyway hope this some what helps until the next revision.

UPDATE:

I spent some more time on the matter to try to get this working better for myself. I reset everything back to defaults. Logged off which of course borked it like a fresh install did for me. Tried a few things and I'm pretty sure i got it working 100% now with only one setting!

First off you need to go to http://shark007.net/ and get windows 8 codec pack (32 bit) as the 64 bit version is required it says to work. You don't actually have to make any changes there as stardock was awesome and indeed made the programs used 64 bit. So we use the 64 bit version of the program to satisfy all of our deskscape needs. Run the 64 bit version as admin. Click on the SWAP tab and change the *MPEG2 codec in directshow players* to the *Use FFDshow's codec*. Click exit - hit the windows key or goto the start menu and right click your user and sign out. Log back in and use all of your mpeg2 deskscapes like before. Enjoy  

My problems expands past that, as I tried what you (SteveFox1620) recommended in the "updated" thread and  and still didn't make a difference.

@Neil Banfield I just noticed your post. (I'm on Win8 64 BTW)

 I have tried and deleted LOTS and MOST of my dream collection due to this, but some of the ones I stilll have that give me the error are these:

Snowy Day by Carguy1

Clownin' Around by Carguy1

Rough Seas by CarGuy1

Corbiere Light House 4 by Nicholas Kenny

Red Sea by Master Baron

Red Giant by Master Baron

Winter Paradise by Amitsaran

Here's the results. I highlighted the obvious. Is this the problem? How do I fix this? Thanks!

LAV splitter worked but caused some issues. only ddshow is being used while running the mpeg when working correctly. It was enabled and the icon was visable when things didn't work. If you could force ddshow and got rid of LAV it might solve your issue.

Doctorx 3.9.9 i had to use the x64 version since i run win8 x64

@ CarGuy Ha! Awesome. This one worked...and is truly my most favorite (with my former set up) dream. 1.Snowy Day by Carguy1 2. Sea Fish by Amitsaran. 3.Nocturne by Amitsaran. My top 3. Thanks for that. I wonder if this is the problem with the others.

Ok how about monument valley and starburst?....Please?

Its April 2015 and the problem still exists. Why does Stardocks staff not fix things like this? Any new user will experience this problems.

There are significant licensing costs to include MPEG 2 decoders with a product.  Therefore if you wish to use a MPEG2 video you can either use Windows 7 which included such a decoder, or pay for decoders from a 3rd party supplier.

Deskscapes will play any video type as long as there is a decoder installed.

Ouch Wiz...now play nice.