So last night my fairly new self built desktop froze. I restarted the computer, and no display would come up at all. I cut off the power supply and left it off for a minute, which allowed it to display again for some reason. I launched a startup repair, which seemed to solve the problem. I turned off the computer last night, and this morning it booted, then froze on the Windows login screen. I restarted it, and since then I've had a boot loop that I cannot avoid. It doesn't make it past the "Windows is starting screen", and usually loops. However, if I try to launch startup repair, I get a blue screen message with a BAD_POOL_HEADER error and sometimes a MEMORY_MANAGEMENT error. When I try booting in safe mode, I get a blue screen for a split second, then it loops again. My keyboard also only works in the startup menus if every other USB device is unplugged. This came out of nowhere and nothing I've been able to find has been helpful. The fact that I can't get into the operating system makes it especially difficult. I also don't have a Windows 7 CD to Repair with/boot from.