new external Hard drive

[tdeath101]

i have bought an external hard drive and i am trying to run windows xp pro from it but it gives me an error message saying to remove any new hardware added to the computer, if this message appears again after restart please contact blah blah...

the specs for the Hard drive are in this website plz help
http://www.geeks.com/details.asp?invtid=A-AP35U80GB-K1

 

[tdeath101]

my guess is that it would be becouse of the 480 Mbps but don't quote me on that. i also think that usb interface is too slow but my friend has a different external harddrive and he boots up fine so that will be out of the question...