12 GB ram!? Well, if you are unsure about how smooth can be you transition to a full linux user you don't need to install anything on hdd with that amount of ram! Go live! Use any livedvd iso image or usb stick to run a live linux session!
Is not a joke, with that amount of ram you can do a lot of normal linux user work, including gaming, without any need to reboot, FOR MONTHS
! Yeah, you eyes is ok and you read correctly, i done that personally with a very good live distro: Sabayon Linux
Very good to work in prolonged linux live session with almost full usability, i mean in linux you can really upgrade you video drivers in a live session without a need to reboot! Any software upgrade or new install is very smooth in rolling based linux distros like sabayon linux and entropy package manager is very good
If you were still afraid about going to command line for a good use of entropy package management infrastructure and gentoo world you can try Ubuntu family pathway, tested in live session for usual new software installs and causal work or games but not so extensive like my monster live session uptime in Sabayon Linux ( was an aprox. 40 days marathon with usual upgrades and special test for things like live graphic drives updates to see if i can to that )
Unfortunately i can't recommend recent Sabayon Linux version for a final install to hdd because Anaconda installer, used by Sabayon Linux, is really buggy and very unreliable especially for a new linux recruit. For a successful install you need strong linux karma, but fortunately any ubuntu is just good for that.
Because for windows to linux transition kde is the best smoot path for a quick relearning of some os handling jujus kubuntu is a good alternative for a trouble free full hdd install
If you are still interested i can write more about small things that can enable you to test any decent linux distro in live sessions for as much uptime as you want
For example in an live session ubuntu use open source drivers, good for stability but not so good for serious gaming instead sabayon linux is between the few linux distro to use special haiku power to enable that from very beginning so you can use you graphic card power at full potential
But Sabayon Linux iso can't be convinced to boot from an usb stick who use grub as the boot manager, tested personally with multiple versions, and that means you need to pull the dd weapon to do that and now you will use an 8GB usb stick as an 2 GB hdd already 100 used and to recover the lost GB you need another dd shot who will kill the written iso image! In contrast any *buntu family iso is dead simple to setup to be grub friendly and that means an multi distro linux live usb stick with enough free space who can be used by that linux live session to save you work, documents, musics and even movies!
And so on!
So, in short, with so much ram first try a live linux session and see how much you can resist in the linux world. If after some prolonged time you do not give up then is time for a real full hdd linux install