A strange Windows 7 error

[netmask56]

Suddenly my computer running Win 7 Ultimate 32bit doesn't like files with the suffix .mp4 !!!! Windows explorer reloads if I hover my mouse over such a file.

If I click quickly it plays ok..... if I quickly right click and go to rename I can do that. But hesitate and all is lost!!!

If I rename the .mp4 to .m4p all is forgiven!!!

If I put it in a MKV container using MkvMergeGui (no re-encoding involved and takes about 30 seconds) once again it is fine.

I have checked everything malware, virus, scan disk for errors, defrag etc etc... codecs, no new programs

If I do the same from within a program's file selector, say Womble, there is no problem.

I'm happy with the rename regime but I would like to get to the bottom of this.....

[Baldrick]

It's probably an explorer thumbnail preview problem. It tries to preview it and fails/crashes. Try run codec tweak tool and see if it finds any problems. Or uninstall/reinstall codec packs/ffdshow/filters.

[netmask56]

Thanks Baldrick, tried the program and indeed it found quite a few broken links in the Registry. Fixed them up reinstalled ffdshow and Haali but alas my mouse still has the "we don't want to hover on mp4 blues!"

[fritzi93]

Have you tried disabling thumbnail preview, reboot, run a registry cleaner (like CCleaner) and then system file checker from command prompt, reboot, re-enable?

I think the last time I encountered that problem I was still running XP, and the above fixed it temporarily. Until I hovered over a corrupt video file, which I think was the real source of the problem. Disabled preview again, deleted the file, re-enabled, etc. If memory serves, it's been a while though.

Good luck.

[jagabo]

Try re-registering quartz.dll.