Since March this year, my HP laptop locks up with either a blank screen or no mouse or keyboard activity with no way out other than switching off. Under safe mode the machine runs all day and can be used "normally" but when returning to full mode, at some point, maybe at boot time or later when any program is operating, the system stops responding. I have the checked the hard drive for errors as well as using various utilities for memory test with no issues revealed and Event Manager does not show me anything that is suspicious, other than the unscheduled switch off. I have also restored from an image whereupon the machine may work for a few days before the problem re-asserts itself; switching off non-critical services has no effect. The operating system is Windows 7 Pro (32bit) SP1 (upgraded from Vista over a year ago) with McAfee for security and all HP drivers
and the bios have been updated. I reformatted the hard drive and installed Windows 7 64bit but the same problem occurs. As the machine functions in safe mode I assume there may be a driver
conflict but do not know where to start with any further investigations, so some help would be apreciated.