You can take out the battery, but there should also be a jumper that can be shorted for about 10 seconds that will clear it also. Well, my advice to you is once that's done, make sure your memory is set to run 5:4, then go back to 225fsb and start raising it by 4-5 mhz at a time, until it becomes unstable (when it will no longer pass the torture test of Prime95), then go back down to the last frequency that it was stable at, or raise your vcore (processor voltage) and try again.