how much do you mean by cheap,will you be playing games or doing office work,let me have some specs and I will tell you what it will cost, as I have enough parts to build one with windows XP pro operating system.
I have a desktop with monitor, keyboard eyc, operating with office 2007
this was bought about three years ago but it has been in storage for the last 2 years, works perfect £150. let me know if interested and I will pm you my number