Afudos BIOS update tool is for the DOS program, you can't just run it under the win7. If you want to run under win7, download the " ASUS Update V7.17.02 Install Program for 32/64bit Windows XP & Windows Vista & Windows 7". It is under utilities section.
https://www.asus.com/Motherboards/M4A78HTPC/#support_Download_30
If you use the Afudos BIOS update tool , you need boot into the DOS, and run AFUDOS, pointing to the place you stored the BIOS files.
http://www.ehow.com/how_4885286_update-asus-bios.html