My font size in Yahoo are very small. I changed it to 120 DPI but the font on Yahoo are still small.?

How can I make the font bigger for Yahoo?My font size in Yahoo are very small. I changed it to 120 DPI but the font on Yahoo are still small.?
Press and hold down the ';ctrl'; key while rolling the mouse wheel backward and forward to adjust the size to suit yourself.My font size in Yahoo are very small. I changed it to 120 DPI but the font on Yahoo are still small.?
Click View from the IE toolbar.

From the drop down menu, rest your mouse on Text Size.

Select a larger text from the next menu.