Windows updates have a way of messing with hardware drivers, as they sometimes tend to not be compatible with the hardware made by the laptop manufacturers, be it Dell, Asus, Lenovo etc etc. So the best bet is always first to try and roll back the Upd...
I've installed a new Windows XP including SP3 (don't use the recovery discs). I've also installed all necessary drivers from the levonvo support page (no unknown devices left in device manager). The problem now is, I can't hear a sound from the integrated...