did you get that menu when you right-clicked on the .ttf file? thats what it looks like..
you have to go to START -> SETTINGS -> CONTROL PANEL -> FONTS and in that window go to FILE..
just copy/move the .ttf file to you c:\WINDOWS\FONTS directory
how many fonts have you installed on your system? windows goes ga-ga when you have around 1000 installed...
try uninstalling whole bunch of them or better yet, move like 200-300 of them out of the windows/fonts directory to a different one and see if the "install new font" button will appear.
let me know what happens in any case
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