Firefox and other programs/mouse cursor keep flickering

[Pragtical]

So I changed my settings on my laptop (This PC>Properties>Adv. Settings) in hopes to make it perform better; some of the things I changed were:

-Changed the pagefile space to what was recommended by my laptop (3957 MB)
-Adjusted for the best performance of programs
-Minimized the Appearance options for better performance

I also used Razer Cortex to tweak my laptop as well. After I did all of this I restarted as I was prompted, logged back in, and upon opening Firefox I saw the border of the window flickering whenever I would load a new page. I also noticed flickering of certain programs, mainly fullscreen games. It would show the desktop for a split-second and go back to the game's screen, all while my cursor was constantly changing between the 'normal' and 'busy' phases. The only way I can get the programs to stop flickering is by running them in Compability Mode, which only creates other complications.

I was hoping that someone on here would help me find out what I did wrong, because I've had this problem before and after trying a plethora of things I had no other option but to reset my laptop. Thank you in advance, any help is appreciated.

EDIT: Computer's Specs:

Processor: AMD A8-4500M APU w/Radeon™ Graphics 1.90 GHz
Memory:6 GB of RAM
Graphics Card: AMD Radeon HD 7640G
Operating System: Windows 8.1 (64-bit)1

 

[Pragtical]

Well, I think I managed to fix it....I knew that it wouldn't be caused by anything within my computer's system, so that basically left Razer Cortex as the culprit. It seems as if I mistweaked my laptop; to solve it I uninstalled Razer Cortex, reinstalled it, and did the default tweaks that the clean installation came with. It seems that those default tweaks overrode the bad ones.