The thing is the missing drivers..They may be made not to use a driver and be recognized directly in some operation systems..but if you have a windows xp sp1..(home edition ) ..it will not work so well in what matter the drivers for devices..My advice is to reinstall teh windows and use a windows xp sp3 ..if your computer can not handle the windows 7 one ..and will work ..
Or ..look over the internet and try to locate the driver needed for this hard disk .and install it ...IUt is probably a generic driver , but just missing from your system .
Another issue may be the port used..Not all usb ports work or have power ..or just be a 1.0 port that will not support the plugged device ..try to use another port and see if it works .usually these hard disks are on 3.0 usb ..now a days