Yes, the activation system detects hardware changes but, a new activation is consumed only when doing major hardware changes, and overclocking the same cpu is not considered a major hardware change, like changing the cpu would be.
So, you might see a message stating you need to confirm the activation, but then the system will realize it's still the same PC activating, and not consume any activations.
I've checked your GSX order, and it shows you have used only 1 activation for that order. You also correctly used the "Deactivate" function once, so you were able to install on a new system without consuming an activation, so your net count is still 1, just as after purchasing for the first time.
As explained on the manuals and on the web site, there are no limits on the number of times you can REINSTALL the program, you can uninstall and reinstall an unlimited number of times on the same system, provided you don't reformat Windows from scratch.
There's a limit on 6 activations per order but, they are major hardware changes, there's the automatic reclaim of older activations after 90 days, and you can use the "Deactivate" function, that you already used once, an unlimited number of times too.
