On launching Illustrator CS5 - Error: "Err$$$/ADM/misc/5= The adobe UI font could not be loaded."

I am working on the Adobe illustrator CS5 vesion. When I open the illustrator application, an warning pop up window comes every time. It is giving me an error like $$$/ADM/misc/5= The adobe UI font could not be loaded..... It's very irritating. Please find bleow screenshot for more details. 

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