I have unplugged USB hard drives and I did not have problem whole day yesterday. I will give it a shot next week as well to see if problem is really gone (I am not 100% sure that I got rid of it). It started happening a month ago (and I have purchased laptop over a year ago). It happens right on logon screen, before I type in password. I tried to google it, but I just could not find anything about this laptop switching graphics. G73 Model with Nvidia card does have Optimus technology for switching graphics, but I cannot find anywhere that my Radeon model can do that as well. Is there any way I can determine if my laptop actually have some integrated graphics and it does do the switching, since there isn't any info about it in BIOS or Device Management (I added screenshots of device management, it shows only one card) ht tp://picasaweb.google.com/100231031310701101500/Window7ColdBootProblem - INF Update Utility - Primarily for Intel® 6, 5, 4, 3, 900 Series Chipsets - My version was 9.2.1025 and latest is 9.2.1030, I have updated it now. Thank you. - I am using latest Intel Rapid Storage Technology software already. - That VGA driver is just old outdated ati driver, I am using 8.881.0.0 version. (all drivers and firmware updates for my laptop are being updated on a daily basis by an ASUS employee and maintained in a thread on ASUS forum ( http://www.asusrog.com/forums/showthread.php?1150-G73-74-53-Series-Driver-and-Application-Reference ). That's where I update drivers from. - I will be testing booting without USB devices for a while to see if I still experience problem. If it happens again I will try clean startup and safe mode as you recommended. - I only noticed it happening when running with AC, since I never use it without AC (I run it a bit on battery only once in a while so battery doesn't fail) P.S. Thank you people for all the help, I have several ideas that I can test now and to see if any of it works. I'll let you know how that goes. If anyone get any other idea I would be grateful. Cheers.