[cles]

make sure to check for compatibilty issues
hard disk find the best value for money cost divided by space
or format and recycle
depending on your needs a super mulit burner is really convinent and is quite reasonable in my country
ram wise look at the speed as well and also check if other parts cam cope with it
processor get a reasonable dual core unless u want to run a server
or an overly powered calculator if not the power is really wasted espicialy if u want to get a reasonably cheap com
a free os is nice and u learn a lot about how to use it
and linus is cheap and dont suck your com power