This is the strangest thing ever happened to me...
I have an external harddisk drive (ext-HDD), bought around 2 years ago (don't know whether this is an important issue or not).
Here, I have a video file (.avi) in my internal harddisk dive (HDD), it worked very well, then I copy it to my ext-HDD, but I couldn't run the file directly from my ext-HDD! I tried to copy it back to my HDD (from the ext-HDD), and now the copy couldn't be run on my HDD too. Remember that I copy the file, so the original one was still there.
I tried to go to safe mode (forget to mention, I use Windows 7 Pro), and this is where the strange thing happened, the copied files (both in ext-HDD and HDD) can be run in this safe mode.
So, my question is, what could actually be happened there?
PS: My ext-HDD is Axioo, 250 GB, exFAT...
Edited: Currently I used MacOSX, and the file in the harddisk still can't be run. I haven't tried safe mode for Mac (is there one?), but will try later (if there is)