problem playing wmv & wma type files with windows media player   

I have a problem with my desktop computer and I wonder if you can help? I 
have a problem playing wmv & wma type files with windows media player. At 
present I have Windows media player 11 installed. The problem is that when I 
try to play a video file it plays ok but is very feint, like I had turned 
down the brightness and or contrast. All other video functions are fine. I 
can surf the net, view pictures, watch DVD's, all work perfectly. I have 
transfered the particular wma file that I wanted to watch onto my laptop and 
It plays just fine using Windows media player on the laptop, so the file is 
ok. Mind you it,s not just one file, all my video files are the same. That is 
they play but are very dim. 

   I have uninstalled windows media player from the desktop and installed a 
fresh copy that I downloaded from the microsoft site, but it has not made any 
difference. I suspect that a registry entry related to windows media player 
settings is screwed, however I am loathed to mess about with the registry as 
I would probably do more harm than good. I know you have a lot to do with 
computers and have a lot more knowledge about them than I do. So I would be 
very greatfull for any guidance you could give me with this problem. 

Kind Regards

date: Tue, 30 Jun 2009 02:56:01 -0700   author:   Walter