I'm not sure if this the correct section for this, sorry if it is wrong. Well now, I'm slowly going loopy with this one. I can't figure it out at all. Here's my story. I have been using Vista since it was released with not a problem. My family got me a new mobo 2 weeks ago, an ASUS P5K Pro. I also got Corsair 2 x 2 gb ram = 4gb. DDR2 P4 3.4gb CPU I use a hard drive caddy, it does not have a tray, the drives simply slide in then I lock the door. It's guaranteed for 10,000 drive swaps. One drive is for XP and Vista in the other. The hard drives are SATA, they are recognised by the BIOS. It was OK untill Wednesday afternoon just past, Vista would not boot from 2 hard drives. When the first would not boot I restored a True Image V11 in another Drive, same result. I Phoned the dealer who told me send it back for testing, I sent it off on Thursday. I re-installed my previous mobo, an ASUS P5AD2-E Premium,. This one also won't now boot into Vista. I put in a harddrive with XP already installed in it and it starts up no problem. All I changed was the mobo and memory, every thing else is the same. And yes, I was very carefull to ensure the cables are connected correctly. I use a NVidia 8800GTS graphics card, I kept the previous graphics card, a Radeon 1950XL so I fitted this to eliminate that side of things, the boot problem persisted so it's not the graphics card. I let the Vista install DVD check the ram with no problems, but I changed the memory anyway in case Vista missed something, it's the same. The hard drives that would not boot I wiped, formatted and re-installed Vista, but when it came to the part of the installation for the hard drive to boot it would not Every time ( with Vista ) after the BIOS had kicked in, the boot into safe mode message appeared, it would not go past that. On about 3 boots a blue screen appeared at the top of the screen for less than a second. My PSU is a Targan 650 watts. All fans are working. Surely it cant be drivers because the installation did not get far enough into the installation so I could install them. If there was a short circuit with the mobo or elsewhere it shouldn't allow XP to run. The drive that works is a WD Raptor, 10,000 rpm 150gb. Those that won't are Samsungs, they have not given me any problems. It would be unlikely that 3 would fail. I'm now getting one beep shortly after the PC starts and before the BIOS kicks in, this is using XP, it's an AMI bios. One beep indicates = Keyboard controller error, or a Refresh Time error or no master drive detected. The master drive is detected, and the keyboard is working OK, well, I find no fault with it. I do not know what the Refresh Time Error is is or where it is or anything about it. Any help very greatly accepted and thanks in advance.