Well if it is an Intel CPU the most likely thing is that a BIOS upgrade will be required.
What you are describing sounds as if XP is already installed and is not reaching the first Splash Screen. This type of display is common on older slower computers that is about loading XP not the hanging. So since it appears that XP is installed it must have been working at some point so see if you can boot it into Safe Mode by pressing the F8 key before the screen goes blank.
If a BIOS Update doesn't cure the problem you'll have to go in through Safe Mode and remove the last thing installed as that will be what is causing the problem. There where quite a lot of pieces of hardware that where not XP compatible going around a little while ago and this could also be part of the problem. Look specifically at Samsung DVD/CD Players/Burners and video cards while they may work with a pre SP1 install of XP they will cause the MBR to disappear when SP1 and latter are loaded.
Col