>My define windows commands doesn't get fontname and fontsize properties from main forms's or _Screen's default.Is there any way for that? In the other case I have to fix all define windows commands...

IIRC there is a potentially confusing bit when dealing with positioning and sizing of legacy DEFINE/MODIFY WINDOW command. Positions end up relative to parent window, but the sizing is determined by the window's font. When you use:
DEFINE WINDOW WinName FROM Row1,Col1 TO Row2,Col2 FONT FontName,FontSize
you're defining upper left and lower right according to parent window font. Depending on what the font parameters you're using you might not get what you're expecting. If you were to use:
DEFINE WINDOW WinName AT Row,Col SIZE NumRows,NumCols
the position of the window is dependent on the parent window's font, but the sizing is relative to the window's font.

Obviously in DOS it's assumed you're working in a monospace font, whereas in Windows most fonts tend to be proportional. This could potentially throw a wrench in the works if you're not careful about screen coordinates.

One thing that I'd discovered -- the metrics of bitmap fonts gets really weird at times -- especially when your design-time font sstting differs from the runtime enfironment (e.g. you design in "Small font" and user is running display as "Large Font"). Screen coordinates are a bit more predictable if you use a TrueType font while designing.