I tried using Stormjumper's clean uninstall and removed 126.96.36.199.
I downloaded 188.8.131.52 again and installed it. Still no Preview video.
Did a clean uninstall again, put on 184.108.40.206 and still no Preview video.
The only other software on Win XP SP3 is WMP 11, because I only put it on so I could use DVDFab. And Preview was working before.
Anyone have any other ideas?