The font used by the ribbon does not match the font the user has chosen as their Windows preferences (which is the preference my application uses). This means that as the font in Windows gets bigger, the ribbon gets smaller.
Notice how the ribbon gets smaller in each screenshot:
It's also important to note that Outlook 2010's Ribbon does honor the user's Menu Font preference, while mspaint for Windows 7 honors no font preferences.
i want to be more a good developer, and act like the Office team, and not like the MSPaint team.
You can honor the user's preferences, and respect their color settings:
TColor glass = Dwm.GetColorizationColor();
VarCast(v, ColorToUIHSB(glass), UI_PKEY_GlobalBackgroundColor.pid);
IPropertyStore ps = framework as IPropertyStore;
Since the Windows Ribbon Framework is what the MSPaint team uses, I'm afraid you're stuck with the same problem as they are.
Anyway, If your customer has high resolution and have trouble seeing the fonts, the correct way to fix that is to change the DPI settings of windows from 100% to 125% or 150%. This will scale all the fonts, including the ones in the ribbon.