Vgn fs 740/w

Question

I have recently recovered my laptop (instal new windoes by vaio recovery cd) and then my sounds doesn't work I mean is shaking the sound is played like robots I don't know what to do. I uninstaled and reintaled the audio driver (Realtek® High Definition) over and over again but the problem still exists. I confused because after 1 day I turned on the laptop and then the modem was gone i mean there is nothing as modem on my laptop and the windows is not possible to detect any hardware as modem on it.
Please help me.
what happened to my laptop.
regards.
Y.S