First of all, thank you all for you quick answers.
Here is some additionnal info :
ickymay, this is not a Java app, this is a compiled .exe file developped in C++
Drew, these are my display settings :
Control Panel > Appearance and Personalization > Display : there is Smaller - 100% selected
Control Panel > Appearance and Personalization > Display : Custom DPI Setting is set to 100%
Control Panel > Appearance and Personalization > Display > Screen Resolution : is set to 1680 x 1050
tblount, I can't resize the bottom part of the application to have it with height increased
Check this new printscreen , I resized the window, the bottom part gets no scrollbar and always take the same space.
I also cannot select all the text to force viewing everything.
What is troubling me is that my colleague has the same OS, same application version, only the laptop is different, and he gots the good display.
Any other idea ?