no go scsci controller

i recently re-installed xp pro for a friend and after this he pulled out a hp flatbed scanner for me to install as well ,which i did not mind.so i turned on the scanner,as this must be done first being scsi connected and booted up the system to ,but the p.c. does not recognise the scanner .so after going into device manager ,i saw that the scsi controller had nil drivers installed and proceeded to try and update or install them with no success.their is no disk with drivers accompaning the p.c.,only audio, chipsets, etc & just xp pro and being a novice need help.if anyone has any ideas as of how to find them ,this would be much appreciated