How to make Windows 8 recognize my new GPU?

A few months ago, I bought a new gaming computer. I didn't think I needed a good GPU because I mainly played Minecraft/Terraria/Older Games etc…

However, I started up a YouTube channel and so I started to play games like Assassin's Creed 4: Black Flag and it was running at about 10 FPS if I'm lucky.

Anyway, I went on the maplin website and bought myself a 'beast' of a GPU (according to reviews) and installed it into my computer. (I made my own computer and so I didn't bother to take it to a computer shop to have it installed).

I thought I had done it all correctly until I booted up Assassins Creed 4: Black Flag and again, it was running at about 10 FPS.

So I then went into control panel > display > change display settings > advanced settings to see what GPU my computer was running, and it says AMD Radeon HD 7560D which means it's running my motherboard GPU…

Anyway, I was wondering if someone could tell me how to make windows 8 recognize my new GPU?

I have updated all of my drivers for the GPU to see if that helped at all (but it didn't)! I'm running on Windows 8 if that helps?

-Tom (TomTheCubeGaming)

It can't be done. Sorry!