There are several ways to solve this.
1: C:\Windows\Fonts find and delete the font from there first and then delete it from system folder.
2: Open Fonts by clicking the Start button , clicking Control Panel, clicking Appearance and Personalization, and then clicking Fonts, click the font that you want to uninstall.
3: Rename the font and then delete it.
4: Cut and paste the font somewhere out of the folder and then delete it.