|Don't worry take your time, if you need help installing the card then read these steps.|
1. Turn off computer and disconnect it from the mains and hold down the power button for a few secs.
2. loosen the thumbscrew and remove the side cover ( when facing the back it should be on the right ).
3. On the back of the computer at the bottom there should be some covers and another piece of metal holding them down, unscrew the piece of metal.
4. Inside the computer, lie it down on the floor, the last right cover needs to be taken off.
5. Get the graphics card and put it in the black slot on the motherboard and screw the piece of metal that you took off, back on.
If you don't understand any of it or you don't know what i'm on about, tell me.
By the way, try the video on win7, see if its improved.