I spent ages looking for a fix for this and found many forums and many “fixes” which worked for some and not for others. Something that I installed (or maybe un-installed) managed to mess up some registered dlls, and nothing I tried from all the helpful suggestions fixed it.
Until today (type these in a command prompt):
regsvr32 jscript.dll regsvr32 vbscript.dll regsvr32 wmp.dll
And wow, I was amazed when media player actually started! So thanks to HighConcept on The Green Button who offered the suggestion. I use mostly iTunes anyway… but it had become annoying with embedded media and a few other things that I was trying to achieve with it.