better go bios for ocing, google for info how to oc , it fun, and no need to worry for bsod when do oc ,it fine,
Do read up before attempting to overclock if u are new to OC. As long as u experiment below the safety threshold it's fine getting bsods until u hit that sweet spot. Take note that patience is needed.
Try 4.6ghz with 1.2v cpu voltage. If can, Ho seh liao. If cannot, try 4.5 with 1.2v. If can good, then stress test. If not will be 4.5ghz with 1.25v.