for your sound....
you say you formatted the computer and I think you did it with a windows xp cd!!and when you try to install drivers this problem has come..i know cause this happened to me before..first question is:did you create your own recovery kit ?to do tihs go start-programs-vaio recovery tool.this will create recovery and drivers dvds.but I hope you didn't format the disk using fdisk!!!if you did this mean you erased hidden recovery part on your disk..
do you have recovery kit ?if you have it remove sound driver and restart pc..and in the dvd there is a folder named hotfix!!install everything in it..and than pc will recognize your sound card..