Installed Flash9 Alpha, Then Flex2 trial, all video players
ceased being able to play DVDs, (powerDVD, Real, Windows). restored
computer to before installation and DVDs worked, re-installed
Flash9 Alpha, tested DVDs and they worked. installed Flex2 Trial,
tested DVDs immediately afterwards and they worked. Next day
players stopped working again. restored to date prior to flex,
keeping Flash9 Alpha, DVD players work.
Turned out to be the NVidia GEforce Graphics card I had
installed, which was necessary to support the also recently
installed After Effects, not being compatible with everything else
in my system that required graphics, (at least not at the same
time). Conflict between NVidia, 3D programs, playing DVDs and all
video players was partially resolved by downloading player updates
at Dell resources. Now programs work, DVD/video works, NVidia
properties manager still buggy.