Laptop had lost a drivers

Hello,I've Satellit M305-S4826.Six monthe--perfectly! Then,I had the blue displ.(error.....bla,bla,) -- the master sed:some party of HDD was killed by some virus. O'k. I've a new Windows,but my laptop had lost some drivers for sound-volum, for connect with Internet connection. I'd sow on disk-nothing. If somebody had seme probl.,or now where and how to take the drivers---call me please.