Hmm, 'could' be the reason,

to be honest, without checking
though, can't say for sure, but in all honesty, all installed progs 'should'
go into your C:\Program Files Folder not the
C:WINDOWS\ Folder as that is normaly used for the windows
system-progs etc.
Uninstal it all and give it a try
Ray
PS
As for plugins, you certainly need the MED.DLL
( iv_mmedia.zip )