M2TS won't play on one PC?

[cncb]

I recently set up 2 PCs with an identical re-install of Windows 7 Home Premium (only difference between them is Intel HD 2000 graphics versus just plain HD graphics, Core i3 vs Pentium). I have several movies in the M2TS format that Inexplicably won't play in WMC or WMP on the Core i3 PC. You see a brief flash of the video in WMC and then it shows a blue screen with this text: "Cannot Play Video; Windows Media Center cannot open the file". It can play MKV files and WTV just fine so it doesn't appear to be a network problem. The other PC plays the M2TS files fine so any ideas why playback is screwed up on the Core i3? Thanks.