You can:

Copy what's on your HDD to the SSD with a Cloning device

Or

Install Factory OS with Asus BackTracker

Or

Install a fresh copy of Windows 8.1 straight from a virtual disc.



You don't need to install 8 then upgrade to 8.1, I find that causes problems and would rather get the latest package in one simple install.


DO NOT FORMAT YOUR ORIGINAL DRIVE (WITH ALL YOUR INFORMATION UNTIL YOU KNOW THE SSD WORKS AND BOOTS TO DESKTOP

You'll POSSIBLY need to link your SSD to your motherboard manually via the BIOS, I don't yet understand how to do this, so when you try to Install Windows and it doesn't work, shoot a message here and someone may be able to guide you. *Looks at hmscott* ;d

Download and run this http://www.datafilehost.com/d/829c7acd (UNTICK THE DOWNLOAD MANAGER) if you want to keep a backup of your original Key if your installation doesn't recognise it. Write it down, and copy paste it to a notepad onto your phone or something, or even take a screenshot and email it to yourself. This is important in case sh!t hits the fan for some stupid reason.

Once you've got your CD Key, paste it inside this http://d-fault.nl/PidCheck.aspx&from=litvz while selecting 'Windows 8 and server 2012

Your result will tell you what you need. Fill in these blanks for us here below. I'll try find you the appropriate disc needed.

While your Windows Key is tied to your motherboard, thus pretty much impossible to steal, do not publically post your Key as a safety precaution.

Edition Type :
Description :
Edition ID :
Key Type :
Crypto ID :


CD KEYS:
Generic Key Windows 8.1 Core:
334NH-RXG76-64THK-C7CKG-D3VPT

Windows 8.1 Single Language
Y9NXP-XT8MV-PT9TG-97CT3-9D6TC

gvlkCoreSingleLanguage
BB6NG-PQ82V-VRDPW-8XVD2-V8P66


Your BIOS Product Key will not work for the installation, so depending on what disc you need to use one of the keys above to continue with the installation process, depending on the disc you get. I'll assume you're Core edition, so the first key will work for you.


Note: I've been told by a few people that posting links to ISO's (if you need one) is illegal, however if you have no other choice than to download an ISO, then I'll shoot you a PM on where to get the ISO you need.

The best thing to do with the ISO is 'burn' it to an 8GB USB using Rufus or any other USB Boot Media Writer, then deleting it once finished. I wouldn't keep an illegal hard copy.. besides, you probably only need it once. ;d

Also, I don't believe your CD (if you have one) will work with your current key, and I am unsure if you're able to overwrite it with your own personal key that came with the disc (and if you do) void your warranty.