How to change font sized

Página Principal
Anexos:
Mensagem como email
+ (text/plain)
Apagar esta mensagem
Responder a esta mensagem
Autor: j
Data:  
Assunto: How to change font sized
Where would I change the font size for my display. I am running Mandrake 8.1    
The main thing is increasing the size of the letters on the screen so i can
see them better.

Changing the overall font size, would that also change the size of what I see
in VI, emacs, and NEdit ?

Thank you]

Roger