For some reason, I can't play HD video clips any more on my laptop. I have
Windows Vista, WMP 11, and have the capability to play HD clips.

Just a few weeks ago, I was able to run 1080i .wmv files, but now those
won't work. Instead, I get audio, but no video. When I try to play them in
another player (such as VLC Player), I get the video for a second, then it
freezes, and I keep getting audo. For 720p clips, I get audio and video, but
now the picture seems to be over-exposed or super bright.

I installed VistaCodecPack just a few days ago, but uninstalled it after I
found out about these problems. Is there a specific codec I need to make my
HD clips work properly again?