quicktime won't open almost any movie
hi, i have several movies which have .mov or .avi files extensions, bur quickitme won't read them.
i tried convertinge them and other movies with .mkv extension with smartconverter but that won't work. I also tried upgrading quicktime with flip4mac but that won't work either. any advice? txs
MacBook Air (13-inch, Mid 2012), OS X Mountain Lion (10.8.2)