Hi,
I have copied some home movies in H.264 (HD DVD) format onto my hard drive in order to edit it. Despite purchasing a ATI Radeon Sapphire HD PRO 2400 graphics card with 512mb DDR2 the video still stutters and greatly lags behind the sound. I have tried different codec settings using ffdshow and media player classic aswell as Windows media player and Nero movie maker, but still no joy. Do you think my hardware is up to it?. I have an Intel Celeron 3ghz processor and 1g RAM on a Compaq PC. Hope you can help.

Did you uninstall and reinstall the ATI drivers?

I don't recall uninstalling the ATI driver originally. Just in case, I uninstalled and re-installed and the latest one appears in the device manager. There was no change in performance, ie the video is much slower than the audio. The HD video uses about 97% of the CPU on playback.