take the cmos battery out for like ten minutes and then put it back in and reboot. that should clear all bios settings back to what it was.
There should be jumpers near the battery. If you don't know what you're doing, then simply taking out the battery is your best bet. Alternatively, there are jumpers normall on pins 1 & 2. You have your computer off with the PSU off and put the jumpers on 2 & 3, flip PSU on, Flip the PSU off, put the jumper back to pins 1 & 2 and turn your PSU and computer on. This too clears the CMOS Data, but if you have no idea what I'm talking about then just take out the battery for now