How to install windows xp on i3 processor

It doesn't matter what type of processor you have the windows instal is the same on any PC. Put the Windows CD in your optical drive , restart, go in BIOS setup and put the optical drive first booth device , save and quit.
 
actually i am getting a problem in which the computer is showing that check for virus in your computer or newly added hard disk
how can it be possible that a virus in my computer because my computer is of just few days old