Ok my sister is interested in getting a gaming pc she mainly plays mincraft and civilization 5 which are not demanding tasks but she might get in to some new games that are more demanding. the computer she has plays mincraft at 20 fps and lags a lot to, so she might get a new pc. i have a extra gtx 950 2gb that she can have for free so dont worry about a gpu. so what other components should we get for 400 dollars and under she does not have a copy of windows 10 so u need to include the operating system (her computer now is windows xp so that wont work) or should we go pre built and just get a power supply