Was the user on Torrents or cracked software? Usually that's what I discover but the good new with Apples is we can reinstall the OS and save the files.
You did not reveal which OS so I'll lead with Apple's word about this.
I thought this might be common new bug but can't find any info on it.
I have a new MBP which I bought a few months ago. About 2 or 3 weeks ago I started having trouble with all my video files.
I can't think of the proper word for it (I'm not English), but it is like when videos online are lagging. It just freezes for 2 or 3 seconds, sometimes longer, and then plays on.
This happens on ALL my video files, regardless of the file type (I play MP4's and avi's mostly) or the player (VLC, QT or iTunes).
Please help - I can't think of anything I did/upgraded/downloaded that could have caused this.
Thanks in advance,