hi every body i recently installed ubuntu 12.10 on dual boot with win8 on my Lenovo Z570 (core i5 (2.50GHZ) 4GB DDR3, 500GB HDD, and dual GPU intel and NVIDIA GeForce GT 630 M)

My problem is that ubuntu freezes randomly i thinks its a hardware problem (i tried opensus and Kubuntu but the same problem)
i don't know how can i diagnostic the problem

Thanks in advance