Two graphics or a new one

Here is all the information when I bought my PC:

Intel Core i5 3470 3.20GHz, Intel H61 Chipset, 4GB DDR3 1600MHz, 1TB HDD, CoolerMaster Elite Power 430W PSU, On-board GFX, OcUK DVD-RW, Onboard Audio, Antec 300 Case, Stock Cooler

https://www.overclockers.co.uk/showproduct.php?prodid=FS-178-OE

Your case seems to be of a large enough size to handle a full size video card.....so that's a go.

The elite series of psu seems to be of the dual rail flavor.
Without knowing the power distribution of those rails and the amps on each rail I can only guess.
Here's my guess.
It should be able to power the hd 7750@60w
It might be able to power the hd 7770@80w.....more video power/fps.....your call.

Thanks for the help.

I have someone who is willing to set up my graphics card because i have no clue, however, if this is a double rail, that will allow me to use 2 graphics cards?

Say for example, it could hold 2 graphics card. Would there be a risk of over-heating and would it make my performance better, for example, making my fps higher while gaming on high settings?

And given the great performance of the single 7770 why 2 cards?

OK, if you are going with 2 cards, most of the time I see over double the power rating and find 1000 Watt PSUs all too often.
Bob

Does that mean that it could possibly overheat or would be pointless?

I'm just trying to make the most of my money and try and hopefully get a better understanding.

I wouldn't like say, like to run my game in HD and fun of 40FPS for example, as if I used my other graphic cards I could run 60.

So using the two cards would maybe cause problems?

thanks everyone for the help!

"if this is a double rail, that will allow me to use 2 graphics cards?"

No.

Not only no because no one should warrant such a setup, you also need to check if your machine has the slots to hold such.

And I'm a bit lost why you want to go down the dual card road given the benchmarks I'm seeing on the 7770 listed in the link above.

Bob