^If I remember correct that occurred because of Windows 7 using EVR renderer which does not do a high quality scaling. Windows XP and Vista used VMR/EVR 1.1 (older versions) that used slower but higher quality algorithms for the same (with higher CPU time). AFAIK this should have been fixed with later drivers, however you can easily bypass it by using photo viewer software with their own renderers, or in case of videos, replacing EVR with ffdshow, madVR or some such.