Hey guys, first post. I've been having a a lot of computer problems the past 3 weeks and it's really gotten old. 3 weeks ago, after coming home from vacation, I plugged in my desktop and it wouldn't turn on. It had a light on the back of the case and a light on the motherboard, but that was it. I took it to the tech department at my high school and we tested the psu with a multimeter and found that it had power and then went on to test virtually every other component and decided that it was the motherboard. I ordered a new one-the exact same model I'd had-and it still wouldn't turn on. We grabbed an old power supply and all of a sudden we had take off. However, the hard drive started making that clicking noise that is rapidly followed by death and, low and behold, it won't go past the dual boot screen. So I grabbed an old hd with xp on it and tried to boot into it. It made it to the first screen but froze. I grabbed a Linux cd and tried to replace xp but every time I turn on the computer I get this error message "AHCI BIOS not installed!" and it boots straight to the hd even when I change the boot order to load Linux. When I unplug the hard drive, I still get the error message, but the cd loads fine. I have a Dell Inspiron 518, nVidia 9600 gt, 2 gb ddr2 Ram, 350 watt power supply (the fresh one; the old one was 300w) 250gb hd dual booted windows 7 and vista. As a side note, when the computer would still boot a month ago, for whatever reason, I had to let my computer boot to a cd and then exit before it'd boot to windows 7. Vista booted fine. I don't think it's related but you never know. Thanks in advance.