iamtanz :
USAFRet :
Whichever is cheaper. If you buy it and install it, the only difference is who you can call for 'support'.
Retail = you get to call Microsoft
OEM - you get to call you
As the possibility of having an issue where you need to call Microsoft is so tiny.....it's not worth any extra money.
But in retail can i fix it too just myself? and do you think windows 8.1 non Pro is good too?
Yes. But if 'Retail' is more expensive than OEM/System Builder, there is no reason to spend that extra.
And as far as Pro/nonPro....Win 8 Pro gives some corporate level features. ability to join a domain, Remote Desktop Connection, etc. If you don't need those...not worth the extra money.