Can't change file format
Earlier today I tried sending a piece I had written with Musescore version 1.2 to a friend via email on my Windows Vista. They replied and said that they couldn't open the file properly so I tried changing the file by going to File-Save As-Save As Type-PDF-Save. But when I go into my documents and find the name of the piece, it still says .mscz. I've read the 'how to' in the handbook over and over but I still can't change it. Sorry, I'm new to this thing, but how can I actually change the format?