How to change the default system font in Windows 10 Both Windows 7 and Windows 8.x let you set which font to use throughout the operating system. Windows 10 however, restricts users to Segoe UI. This is a nice typeface, and it gives the operating system a modern look, but if you would prefer to change the font to something else -- Comic Sans for example -- you can with a registry tweak. To change the font, right-click on the desktop, select Personalize, and click Fonts on the left-hand side. Decide which font you want, and then Open Notepad. Paste in the following: