I have Finale 2012, Songwriter 2007 and NotePad on my Laptop. I am finding that Charts I wrote years ago on these versions are suddenly incompatible with any of them. I don't know what has happened. They are .MUS files. They apparently need to be BAK, and since none of the versions can load them I am unable to do anything.

Any ideas? I have years of music here. It's frustrating. HELP!

My operating system is Amd A8-6410 APU. 64 bit. Windows 8.1. On a Toshiba Laptop.