Installing new motherboard and CPU, first time

[classik]

I'm replacing parts in my computer for the first time, and I'm still trying to figure out exactly how I should do everything. I'm pretty sure I can follow the steps on actually putting the pieces together, but I'm not sure what I need to do as far as getting the computer to run goes.

The old parts I'll be replacing are:

-ASUS M4A79T Deluxe AM3 DDR3 AMD 790FX ATX AMD Motherboard

-AMD FX-5000 Quad Core CPU

The new parts are:

-ASRock Z77 Extreme4 LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard

-Intel Core i5-3570K Ivy Bridge 3.4GHz (3.8GHz Turbo) LGA 1155 77W Quad-Core

Since I'm running two crossfired HD 6770s, I am also considering replacing my PSU (Antec BP550 Plus 550W Continuous Power ATX12V V2.2 80 PLUS Certified Modular Active PFC Power Supply) with this:

-CORSAIR CX750M 750W ATX12V v2.3 SLI Ready CrossFire Ready 80 PLUS BRONZE Certified Modular Active PFC Power Supply

I am not sure if I need to upgrade the PSU, but I should mention it at least.

What do I need to know as a first-time upgrader? I'm mostly confused about the drivers and getting Windows reinstalled. Because my computer was built for me, I don't have a Windows installation CD.

 

[classik]

You will need a windows DVD because when changing the MB a fresh install of the OS is very important. A new PSU is also a great idea.

How do I do a fresh install exactly? I'm assuming I need to do it because of drivers I had for the old hardware, right?

 

[classik]

Get the windows DVD.. insert it in the drive... boot off of it and follow the instructions.

Ah, sorry. Thought I would have to do something to my original install beforehand.

Thanks for the advice.

 

[classik]

Alright, one more question for now. Do I have to manually uninstall any drivers or stuff like that for my old components? I doubt that having the old drivers lying around would be a good thing.