I have a Sony VAIO PCG-8P1L laptop that only says "OPERATING SYSTEM NOT FOUND" on boot. BIOS still tells the correct time so I don't think its the CMOS battery. I tried to boot to CD (Windows, Ubuntu and diagnostics cd), but I don't get an option for boot order on boot. Tried to change boot order in BIOS, but in the boot menu there are four options, all of which are FLOPPY DISK DRIVE. Not sure why, since this laptop doesn't even have a floppy drive. I did try shifting each FLOPPY DISK up into the top position and then rebooting, but it didn't work. Hard drive seems to be okay as I can plug it into a USB HD adapter and see the contents from other system.