Visual C++ :: Change Default Text Attributes (font And Color)

I needed to change Default Text attributes (font and color) . So I wrote following code , UnicodeTextOut function. I called this function once in each 55ms to update the display screen. but I observed that my Screen used to become grey like a crash after sometime . If I use Minimize an Maximize window , the screen was restoring back for some time.

When I thought over the code , I got my mistake that CreateFont initialization should be done once in the program and probably outside the function.

void UnicodeTextOut(int x, int y, CString s, UINT justify,int GreyScaleFlag) {
HFONT hFontUnicode;
HFONT hfOld ;
hFontUnicode = CreateFont(16, 0, 0, 0, 0 , 0, 0, 0, 0, 0, 0, 0, 0, _T("Aerial"));

[Code] ....

Then I shifted the line hFontUnicode = CreateFont(16, 0, 0, 0, 0 , 0, 0, 0, 0, 0, 0, 0, 0, _T("Aerial")); in my screen class constructor and made hFontUnicode global .

This solved my problem as expected. Why a system crash after certain no of CreateFont calls ?