Hi, I have had 3 x BSODs in the past week and from what I gather they all relate to Vista_Driver_Fault and IRQL_NOT_LESS_OR_EQUAL. I have just upgraded to Windows 7 from Windows Vista on my Macbook and also increased my ram to 4gb (Apple compatible Kingston KTA-MB1333/4G). I've run Windows 7 Memory Diagnostic Tool which says my memory is ok. My macbook is also having problems waking up from sleep, apparently this is quite a typical problem but I've since prevented the screen from switching off which helps. Not sure if this has anything to do with my BSODs. Appreciate your assistance!