Hy guys! I have a Gigabyte GA-K8NF-9 (Rev.1) Motherboard. I had BIOS version F2 and i tried to flash it, so i downloaded the latest BIOS from the manufacturer (F11) and used the @BIOS app that comes with the motherboard. It started the update, but at 50% it gave-me an error message (don't remember exactly what). I restarted the PC.
Now... it starts the BIOS tests, it sees the HDD, DVD-RW, video card etc... but whenit should start Windows... it says CHECKSUM ERROR. Press F1 to continue or DEL to enter Setup.
If i press F1 / DEL the screen goes BLACK and a cursor apears in the top-left corner... and... it's DEAD! Please! HELP!

I think Gigabyte have an option to update your BIOS without going into windoze called Q-Flash.
Press the 'End' key just after you turn on your computer at the point you would normally press 'Delete' to go into the BIOS.

Not all Gigabyte motherboards have this option, but most do. You'll need to put your new BIOS on a USB drive which needs to be in the FAT32 format (they all are so don't worry about this). Check your manual for details on how to do this.

Good luck :)