Inac stiahni si najnovsie verzie prehravacov, podla moznosti urcene pre vistu, mozno musia programy vo viste pouzivat nejaky novy interface ktore stare verzie prehravacov nepoznaju.
http://en.wikipedia.org/wiki/Video_Mixing_Renderer
Windows Vista ships with a new renderer, available as both a Media Foundation component and a DirectShow filter, called the Enhanced Video Renderer (EVR).[32] EVR supports DXVA 2.0, which is exclusive to Windows Vista. [33]
WMP vo viste ti ide v overlay alebo v nejakom HW mode? (Pozeraj vytazenie CPU pri prehravani).
P.S: skus nainstalit do tej Visty aj posledny DirectX runtime z www.microsoft.com (snad tam bude nejaky aj pre vistu)