Building a computer for the first time

[ShadowJago]

After getting my prebuilt gateway PC I new it was just temporary as I saved up to build a struggle PC. Now that I am able to do so I have several questions since its my first time, those being.
Will this motherboard fit in and work with tower this ?
Can I take the hard drive from my pre-built gateway and put it in the one I'm building?
The motherboard I'm planning to use has slots for CPU power connector and ATX power connectors, will I need to put pins in both or just the ATX one since my tower is an ATX Mid Tower?
Do I need any parts other than my: tower motherboard Ram Sticks CPU Graphics Card? I know I will also need hard drive and Windows 7 if my old one can't be transferred and a 500W Power Supply comes with the tower.
Lastly how would this PC (if not finished, then so far) hold up to newer games like Watch Dogs and Dying Light?
I know its a lot but I just don't want to waste money on parts that don't aren't compatible with others or some other issue.Anyways any answers/links are greatly appreciated.
Thanks in advance!

 

[spooky2th]

That board will easily fit into that tower.

You can take the old gateway drive and use it in your new comp but you will have to load windows from scratch. So, save all the stuff you don't want to lose first. If you have the activation code from the gateway, there is a good chance that you will be able to activate windows again on your new comp.

I would at least get a quad core like this one here:

http://www.newegg.com/Product/Product.aspx?Item=N82E16819113333

You can find them on sale for less that what I posted.

Coupled with the gtz 650, you will have a moderate gaming comp.