laptop advices need help thinking to buy asus

[Zezima]

hello,

Thinking to buy an asus laptop called "Asus X550LN-XO273D"

operating system: DOS<<<< wtf is DOS? and whats the best for laptops?

Its i5 <<< is that any good for playing low quallity games like eurotruck simulator 2 ?

what the fuck do i need to know before buying an laptop for medium quallity games? and what the fuck should i ask the geeks at the computer store?

pls name an good laptop computer brand, prefered samsung,asus,

are windows xp still the best? or windows 8 best? help pls