My dad has a Dell Deminsion 4550. I used all the disks that came with the computer including the resource CD I have reinstalled my dads Windows XP Home Edition. Some of the drivers are missing. 1) Ethernet Controller 2) Multimedia Audio Controller and 3)PCI Input Device I managed to find the Bus Driver! I am unable to get it on the internet to download a Driver Helper and of course I have no idea what hardware is in it. Can you please help me? What can I do to find out what he has installed and where to find the drivers? I am sure the system has not been upgraded.