Upgrading to Windows 8.1 Help

What OS do you have now?

Well if you don't mind installing your apps again, I would do it this way.

First create a Secure Erase USB stick or CD / DVD in Samsung Magician.

Shut down and disconnect your HDD, so we don't have any accidents. Then boot from the USB or CD / DVD that you made and erase your SSD.

Then install Windows 8.1 to your SSD still with your HDD disconnected. Do all the driver installs, updates, app installs etc, just like you would if you were starting fresh. If you don't like the Metro user interface of Windows 8, have a look at Classic Shell.

Once that is all done and you're satisfied that everything is working properly, then shutdown and reconnect your HDD.

Then you'll want to relocate your computer documents (music, documents, videos, etc) like this:

Move your Personal User Folders

Make sure to point to them to the appropriate folders on your HDD.

As for STEAM what I did was make a backup of the STEAM folder on your HDD (or just rename the base folder STEAM is in). Then download and install STEAM on you HDD. Login to your STEAM account. Once you have STEAM running properly, then shut it down. Copy / Paste the contents of your backed up STEAM folder into your new STEAM folder (copy because if you mess up, you still have your original). Then restart STEAM. One by one do a game cache verify on all your games. Once that's done run them one at a time. Some games will start to download prerequisites when you start them the first time like MicroSoft Runtime, DirectX files etc. If any of the games has trouble launching, try restarting your computer and try again. This worked for me when I did the same thing you're doing. Well almost the same thing. I built a new computer, but re-used my SSD and HDD from the old computer.

The non STEAM games will have to be re-installed. Offline games, you will lose any progress etc, not to big a deal I hope. Any online games will likely have all your progressed backed up, so once you login in it should sync with your newly installed copy of the game.

Hope this helps. Please read over all the instructions including the link I provided. Don't proceed with this until you are satisfied that it will accomplish what you need and you are comfortable / understand all the steps. Also feel free to ask any question you need answered before you start. Once that secure erase has started, there is no going back.