Dell Optiplex 980 Ethernet Controller.

I did a clean install of Windows 7 32-bit on a Dell Optiplex 980. I don't know what driver is for the ethernet controller. Will you tell me? I just downloaded the INTEL_825XX-GIGABIT-PLATFORM_A06_R290983.exe (5MB). I don't know if this is it. I will try on Monday. Should I update the chipset driver too? What is the driver for that. I downloaded Intel_AMT-HECI_A05_R304259.exe (10MB). Is that right for the chipset?

Also, I often have trouble finding drivers for clean installs. Can you recommend a utility to help find missing drivers?