Hi, this will be my first post, I hope somebody can help me with my problem.
Recently I tried to overclock my AMD A8-4500M processor with AOC, but now for some reason the ''Control Turbo Core'' button greyed out and I cant get it to work again, also my GHz was 2.3 but now it is at 1.9. I tried re-installing AOC but nothing happened
That is why you shouldn't Overclock Laptop processors or GPUs. Laptops aren't designed to be overclocked due to Power and Temperature restrictions.
I would suggest to "reset" the processor with whatever program you used to overclock the APU and uninstall the Overclocking software. Then go to BIOS and see how you can "Reset" your laptop BIOS back to "Default" or "factory settings".
Your APU is considered to be "legacy" old and non-supported by AMD with any more updated drivers. The last AMD Laptop driver for your APU is from 2015 (WHQL) or 2016 (BETA). You can download it them from here: A8-4500M with Radeon™ HD 7640G Drivers & Support | AMD
If your Laptop manufacturer's driver are about the same years, it is best to install those since they are 100% compatible with your laptop.
Not sure how to Reset a Laptop's BIOS back to default, you may need to consult your laptop's manual. Also I would be sure your laptop has the latest BIOS installed and CHIP Set from the laptop's manufacturer Support site.