First of all is have you read this thread first before you attempt to overclock.
There are many dangers to it and I would suggest not doing it until you know what you doing.
Ok what cooling do you have if its a stock cooler you should be able to get up to 3.5Ghz stable even a bit more.
If you have water then over 3.7 GHz should be easy.
Start by increasing your FSB by 5mhz each time and see if it boots up into windows then run a few games to see if anythings wrong.
If it runs perfectly then its stable otherwise if it restarts lower the FSB back down and run a few thing again.
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