So when I purchased a Pentium D E5200, I was under the understanding that this was a 64bit CPU. I put everything together and I want to install 64bit Vista and I keep getting BSOD (Blue Screen of Death) pointing at some ACPI.SYS issue.
So I stick in my 32bit Vista and that installs just fine.
So my question should be obvious now, is a Pentium D E5200 not a 64bit CPU? What is this "Intel® 64" technology that this CPU is sporting then?
I'm guessing you're probably having some trouble with your RAM. What are your complete system specs? Have you manually set the RAM speed/timings/voltage to the manufacturer's specs in the BIOS? Have you run Memtest86+ overnight to test for RAM errors?
I'm having the same problem. When I purchased the computer it came with Vista x64, but the other day it froze in middle of installing Windows 7 x64. Now the only thing that will work on it is 32-bit XP. I've tried two different 64-bit Windows 7 discs and a 64-bit Ubuntu disk, but I just keep getting an "Unbootable Disk" error.