Of the 3 things I listed, were you able to do any of them? If so, which ones?
If you still can't change anything, go to 'advanced chipset features' in bios & change the 'bios write protect' setting to disabled (if you can). This should only be need to be disabled if you are going to flash the bios, but try it anyway.
Also, have you tried clearing the cmos? (JP1 jumper, bottom right corner of your mobo)