Thank you for contrib. Can't do full test for now, but one word have to say:
very bad idea to do windows without caption bar (can't drag window).
EDIT:
in settings place button to select A6 dir or take that path from registry (substring of HKCR\Applications\med.exe\shell\open\command, can't find else way, like in HKLM\Software or HKCU\Software as usual)
EDIT2:
in installer don't hardcode 'Programme' (good free installmakers like NSIS or InnoSetup can automatically detect 'Program Files')
when your program looses focus, i can't switch back to it (with alt+tab or mouse click)
when new proj created and not saved it can't be loaded again (has 'label45' in last line )