Move the contents of the Fonts folder to an empty folder. By opening the Fonts folder, select all the fonts, copy them, and paste them to a new folder. 

Open your registry and find the key below appropriate to your operating system. Highlight the key and press DELETE. Once the key has been deleted create a new key to replace it, by selecting Edit | New | Key and name the new key [Fonts]. 

Restart the computer, then re-install the fonts by opening the Control Panel, double-click on 'Fonts'. And from the File menu select 'Install New Fonts...' adding the fonts that were previously copied to the temporary directory. 

Windows 95 
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Fonts] 

Windows NT 
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts] 

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