I am at a loss as to why I can not install Windows 7 Pro 64-bit on a new system. The installation seems to proceed normally. I see the following steps checked: Copying Windows Files Expanding Windows Files Installing Features Installing Updates I then see: 'Completing Installation', but no check-mark. It reboots, and I see 'Starting Windows' with the Windows logo. Then 'Setup is updating registry settings' with the Windows logo. 'Setup is starting services' Then I see 'Completing Installation' again. It reboots (I wait about 3 minutes before getting the POST) I then see 'Starting Windows' with the Windows logo. Then it hangs, connection to the CRT is lost and shortly after, disk and MB activity stop. I originally had these exact issues with an Intel DG43GT LGA 775 motherboard and Crucial Ballistix Tracer 2x2GB 240pin DDR2 PC2 6400 memory (2.0 V). Intel support noticed that the 2.0 V memory did not match their 1.8 V Motherboard, so I returned the memory and got my current memory - Crucial 2.2GB 240-pin DDR2 800 (PC2 6400) 1.8V. I got the same exact results when I tried to install Win 7 Pro 64-bit with the Intel MB and the 'proper' memory. I proceeded to mess something up in the BIOS of the Intel MB and even though I 'successfully' recovered the registry using a BIOS recovery CD, I never was able to get to the BIOS again on the Intel MB. So I purchased my current ZOTAC GF9300-A-E LGA 775 motherboard. The online user manual for the ZOTAC MB states that it supports the same 1.8V memory that I have currently. However, the BIOS on the ZOTAC has 'MEM voltage control' settings for 1.9, 2.0, and 2.1. It was already on 1.9V (remember that the manual and my memory is 1.8V). I also noticed in the BIOS under 'FSB & Memory Config' > 'MEM Power Features' which is disabled by default. When I enabled it, the memory test ran at boot up and passed. But then after an automatic reboot I see 'Starting Windows' for about 5 seconds, then the system freezes again - connection to the LCD is dropped and MB and HD activity stops. Things I've tried include: Changing SATA cables and ports. Installing from an IDE rather than SATA DVD drive. Changing the boot order. Changing the BIOS from Virtual Technology disabled to enabled. Changing hard disk priority Enabling / Disabling Quick POST Changing Boot order Disabled APIC - got 0xc0000225 error Enabled IDE Prefetch Mode SATA Operation Mode - IDE (default), tried RAID and AHCI ** I also downloaded a trial Win7 64-bit and got the same results. I was able to install Windows XP Pro 32-bit w/o any issues, on both motherboards. I have concerns about the differences in memory voltage, but the memory tests did pass. At this point have no idea what the problem is. I'm not even sure if this is a software issue, driver issue, or hardware issue. Also, during the Win 7 install, I tried installing what ever drivers would install from the motherboard driver CD, but the results in the installation did not change. I also suspect there's a setting in the BIOS that I need to change, but there are so many settings in there that I have no idea what they do. I don't want to ruin another motherboard. I've tried using the BIOS's 'optimal' and 'fail safe' settings, but got the same results. Any assistance with this 'head-ache' of mine would be greatly appreciated - I've been working on this for more than 3 weeks now. Thanks very much for your assistance! ** on other online forums, people with similar issues to mine resolved them using RAID or AHCI settings. This may be the issue in my case, but I need additional help with this. AHCI resulted in BSOD with error: 0x0000007B (0xFFFFF880009A98E8, 0xFFFFFFFFC0000034, 0x0000000000000000, 0x0000000000000000). Other people turned on RAID support and/or installed RAID drivers even though they had just one drive and it resolved the problem.