mobo has a feature, that if you fail to boot 3 times (i think its 3), it will revert back to original settings. this is to help you recover, just save your settings so you could load back (or write it down)
test after adjusting, overclocking is not a task that is done in a few minutes. be patient, test and test.
just be careful with the voltages, research your max voltage so you dont cross it