MOTHERBOARD DRIVERS LOST?

hello friends.i had lost my motherboard drivers cd.i can't play sound on my cpu.graphics is really bad.and i dont know hw to download drivers from internet.my cpu configuration.intel celeron 1.7ghz. 512 mb ram.40gb hard disk.plse friends help me with ur best answer.if u have direct link of net where i can get my pc drivers plse pass me.