I have a problem with ubuntu 12.04 LTS on my custom tower pc in which the OS hangs at specific points:- - live usb with persistence: hangs when mouse appears. - installed to hard disk: hangs after login, logon sound never plays. i am a relative newbie with linux so any terminal output would not make sense to me :) the pc specs are as follows: - MSI MS-7301 Cuba motherboard - 3GB DDR2 RAM (NOT dual channel) - ATI Radeon HD 5450 gfx card the live usb works fine on all other PC's i tried it on. could any one help me ?