I recently bought a Sony VAIO VGN-S3HP laptop. Ever since I received the unit I have had the same problem. When booting from cold (left for around half an hour), the machine appears to boot (LEDs green and can hear processor) but nothing happens on the screen. If I turn the machine off and re-boot, it starts up fine. This happens whether the battery pack inserted or it is just running off the AC power. I sent the unit back to Sony last week and they replaced the hard disk (?) and returned it. It still has the same problem! Also, it seems to be missing a system32 file?