Ok I just assembled this computer and I already had to replace the motherboard because of a bad 3.3V regulator on the board. CPU: Intel Pentium Extreme Edition 965 3.73Ghz Mobo: ASUS P5WDG2-WS RAM: 4x1GB OCZ PC2-6400 Video Card: ATI X1600XT I'm able to get BIOS up and change and save settings. I'm also able to POST. Everything was going great. I saved all my BIOS settings and then inserted my Windows XP Professional x64 disk in my CD-Rom. The computer restarted and booted from my CD. Windows setup started and started loading at the bottom. Then after it finished loading (? I assume) the screen displayed this error: ----------------BEGINNING OF ERROR MESSAGE---------- A problem has been detected and Windows has been shut down to prevent damage to your Computer. acpi.sys PAGE_FAULT_IN_NONPAGED_AREA If this is the first time you've seen this Stop error screen, restart your computer. If this screen appears again, follow these steps: Check to make sure any new hardware or software is properly installed. If this is a new installation, ask your hardware or software manufacturer for any Windows updates you might need. If problems continue, disable or remove any newly installed hardware or software. Disable BIOS memory options such as caching or shadowing. If you need to use Safe Mode to remove or disable components, restart your computer, press F8 to select Advanced Startup Options, and then select Safe Mode. Technical information: ***STOP: 0x00000050 (0xFFFFFAE008E35CF4, 0x0000000000000001, 0xFFFFFADFE40FC9D8, 0x0000000000000005) *** acpi.sys - Address FFFFFADFE40FC9D8 base at FFFFFADFE40DA000, DateStamp 42435eae ------------------END OF ERROR MESSAGE----------------- Now I rebooted the system and after the computer showed the motherboard boot screen (where it tells what motherboard is being used with CPU) the computer shows a blank screen and BIOS starts beeping continuously very fast. The beeps never stop! I rebooted again and again and the same blank screen and beeps! Then thinking it may be the hard drive I switched my SATA cable to another hard drive I had. I rebooted and instead of stalling on the blank screen it instructed me to insert my boot media as it did the first time. Same thing happened Windows setup started loading, then it displayed the same error as above. Tried rebooting and I got the same blank screen and beeps! I also tried switching out all of my memory one stick at a time, and I got the same beeps and blank screen. I thought I may have been my RAM, but I think it would be highly unlikely that all 4 of my 1GB sticks would be bad. Anyway, I'm really up a creek and could use any help ANYONE could offer! I'm just hoping it's not my mobo or CPU.... Thanks.