For Office you must install a font before starting an Office application otherwise Office doesn't know about it.
how can i use these fonts with MS Words...? i have already installed some fonts
How did you have install your font ?
If the font are installed correctly on Windows, you can use it with all softwares, including MS Word.
To know how to install fonts, look at the FAQ :
http://www.dafont.com/fr/faq.php#win
For Mac users :
http://www.dafont.com/fr/faq.php#mac Look my message just up of yours.

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