Hi,
If you can make it into safe mode, try uninstalling the video drivers and motherboard drivers. If you are moving this hard drive from one computer to another it will cause conflicts because of differences in hardware. If you still have your old setup that this drive came out of, put it back in, uninstall all drivers for systemboard and video, the try it in your new setup. If that doesnt work, you may have to reload windows xp onto this drive and do a clean install. Also, if you have a new video card in your new computer, take it out and try booting using onboard video if your system board has it. Then uninstall old drivers, reinstall new video card, then try again to boot.