Preparing for upgrading

[Madmanchris1]

So I'm upgrading my system from an ITX to an ATX. 

 

The main changes are the case and motherboard

 

Case:Old Bitfinix prodigy ------------- New Phanteks Enthoo Luxe

Motherboard: Old Asus Z87 Pro ------------- New Asus Maxiums Formula VII

 

The rest of the components are staying the same for the time being. 

Psu: Corsair Professional Series AX 760W

Cpu: Intel 4770K

Gpu: Sapphire Radeon R9 290

Ram: 8GB Kingston HyperX

Cooler: Corsair H100i

 

I might upgrade the ram to 16GB of dominator's when I get a chance, might chuck another R9 290 in there at Christmas. 

 

So I was just wondering What I can do to prepare for my upgrade.

I have a Nas 9TB to store all of my documents and media files.

How can I backup my steam games because I have a slow internet connection. 

I'm guessing I need to deactivate my windows 8.1 before I put it on my new system? and create a usb iso from the control menu. 

 

Is there anything that I'm forgetting? 

 

Thanks in advanced! 

[Madmanchris1]

I don't normally bump things but i'm planning on doing this tomorrow so would really like some thoughts, sorry if this is against CoC.