I believe your CPU is a Black Edition which means the multiplier is unlocked as
kurahk7 suggested, it's best to overclock in your BIOS but for this case I'll make an exception.
When you start up AMD OverDrive it should give you a disclaimer/warning message just click OK to that and get into the utility.
The utility should look all black with four big tabs on the top as follows: System Information - Status Monitor - Performance Control - Preference
Click on the Preference tab and just a bit under the top tabs look for and click on/mark the 'Advanced Mode' under "Performance Control Mode", click OK to the warning message then look for and click on/mark the 'Apply my last settings when system boots' under "Misc". Now click on apply button to apply those settings.
Go back up and look for and click on the 'Performance Control' tab. You will now see mini tabs under the "Performance Control' tab, look for and click on the 'Clock/Votage' mini tab. Now with the 'Clock/Voltage' mini tab highlighted, to the bottom left of the utility you'll see a outlined box called 'Clock', look for 'CPU Core Multiplier' slider in that outlined box.
Using the 'CPU Core Multiplier' slider you can now overclock you CPU using what kurahk7 referred to as your CPU multiplier. Move the slider to the right to increase the multiplier and overclock you CPU. Click on the
apply button to the bottom on of the utility when done, next the
OK button to close the utility.
IMPORTANT!
When overclocking your CPU is is advised you get better cooling solution for you CPU commonly referred to as a CPU heatsink. These can be found at your local computer store, don't try BestBuy or big retailers. It is also advise you get some proper ventilation in your system, usually a front intake fan and rear exhaust fan will do if you do not have one installed in the respective areas already; again these can be found and bought at your local computer store. Lastly, it is advised that you make sure your power supply can provide enough power for your system with when overclocking. Overclocking your CPU or other components in your system would commonly draw more power from your power supply.
These are just safely precautions, it's up to you whether or not you want to take these actions. I am in now way responsible if anything happens to you PC when using the AMD OverDrive Utility to overclock your computer. This is is just a mini guide on how to Overclock your CPU using AMD OverDrive, I am in no way endorsing or advertising for AMD or OverDrive trademarks.
Now with all that said and done, looking online I would
not use a multiplier any higher than 17x for your CPU on stock cooling. That results in a 200Mhz boost from your default processor speed and a 3.4Ghz end result for your CPU overall. Anything higher will probably cause instability or heat issues with your system.
Overclockers usually test their system/component for stability once an overclock has been applied, there are 3rd party software specifically designed for stability testing. The AMD OverDrive has a '
Test for Stability' tab but I'll let you figure this one out on your own, I'm too tired of typing right now.
So there you have it, a mini guide on how to Overclock an unlocked multiplier processor from AMD using OverDrive Utility for beginners.
Good luck and have good day.