Windows 8 RTM Upgrade

Hi all.
i go to Online PIDChecker and find out my windows details below:

Edition Type: Core
Description : Win 8 RTM Core OEMM

i bought a sony vaio laptop with pre-installed windows 8 RTM x64.
but i have very problems with it such as not compatibility with some games.(L.A.Noir , Driver SanFransisco)

My Question:
What meaning RTM and What meaning Edition Type: Core?
can i upgrade my actived Windows 8 RTM to windows 8 pro or other?

thanks.

up
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any body can't solve my problem ?!