Overclocking my HP Pavilion a6303w

Sorry to tell you there is no way in hell you're going to be able to OC that cpu in the motherboard it's in now. Not through Bios or Windows. You cannot do it through the locked out bios and no OC software available through windows will be compatible with an OEM motherboard.

I would not recommend you try to OC your CPU with the stock cpu fan that came with your computer anyways. That's a sure fire way to fry your computer in a hurry. And I can almost guarantee you will cause damage doing that even if you did find some magical way of overclocking that cpu with your current setup.

I would say your only option would be to replace your motherboard AND your stock cpu cooler to something like a $30 hyper 212+ or something along those lines. But if your going to do that I would recommend spending $50 on a new CPU. Because I'm not sure what type of CPU you have in your current setup but from the sound of it your probably a few generations behind. Buying a cheap $50 dual core black edition AMD Phenom or something similiar would give you a boost in performance at stock values and make it much much easier for you to overclock using something like the CPU multiplier instead of the FSB. Changing the multiplier is much more "noob" friendly as it allows you to change CPU speed while leaving all other values unchanged.

Here's my advice. Your not going to get anywhere w/o spending a few bucks. BY few bucks I mean new motherboard, processor, cpu fan, and RAM. You WILL NOT be able to OC that processor. Even if you changed the motherboard and cpu cooler only. That OEM processor wouldn't OC for ***. You'd be lucky to get 200 mhz out of it and even then it doesn't have an unlocked multiplier so you would have to screw with the FSB making matters worse. Because I would take it you have no experience overclocking??

Just by cheap. A $50 motherboard, $50-$80 processor, $30 heatsink, $30 RAM, and VIOLA! There really is no other option aside from that my friend I'm sorry