You can easily check the existence of registered fonts. Font files can be placed in any folder. But Windows® can use only fonts that are registered in the system. Thus, you can check your fonts only in one way. Open Control Panel -> Fonts. Double click on every font name and be sure that it's opened without any error messages. If you have no errors then you should not correct the registry as Registry Healer suggests. Simply uncheck the "Fonts" category before the scan. Contact email@example.com for future advices.
If the properties dialog will raise an error then there's a font error in the registry. Does Registry Healer find any corrections?