I recently built two computers with amd fx-4300 processors, geforce 650 ti video cards, generic 4Gb memory, generic power supplies and GIGABYTE 78LMT-S2P motherboards. I installed Ubuntu 12.04 on the systems and began installing various programs I needed. When I was done for the day I shut down the computers and turned off the powerstrip. The next day when I went to start them up, I was getting a boot error. After inserting an Ubuntu live disk into the computer, I checked the hard drive, which opened up no problem and still contained all of the files from the os. The rule out the software I was installing, I reinstalled Linux on both computers, and rebooted, after which point there seemed to be no problem, until I turned off the powerstrip again and I got another boot error when I went to turn them back on. Thinking it might be the disk I was using to install linux, I burned another disk with the same os and tried that, and the problem persisted. The fact that it happened on both systems leads me to beleive that it isnt a hardware defect, but possibly and incompatibility between hardware parts, or a bios issue. Has anyone else ever encountered a situation like this where the os doesn't load after the power supply is switched on and off? If so, what causes it and what can I do to fix it? Edit: It seems that it actually fails to boot every time it is shut down, though it works fine when it is only rebooted. Edit#2: Interestingly enough, if i run a hard disk check from the live dvd, and then reboot with the disk in, it loads from the hard drive, but then after the next shutdown, it does the same thing Edit#3: After doing a disk check and it says no errors, it says to click a button to reboot. When I do this it gives me this message after it reboots, "Errors were found while checking the disk drive for /. Press F to attempt to fix the errors, I to ignore, S to skip mounting, or M for manual recovery" on the one computer I hit f to automatically fix it, which isn't a permanent fix because the drive coninues to have problems, but will boot after i hit f, and then not after i shutdown again. On the other computer, I hit m, and it gave me the message, "Root filesystem check failed. A maintanence shell will now be started. CONTROL-D will terminate this shell and reboot the system." The shell is from the hard drive, not the cd.