Just to clarify is this Motherboard brand new or did you buy it used?
If you bought it used then I would highly recommend clearing the CMOS: based on the information provided clearing the CMOS on your motherboard is Jumper based.http://www.asus.com/Motherboards/M5A78LMUSB3/#support_Knowledge_219487F5-9FAF-4349-9BE8-B83C2E6E7565
You can also try loading fail safe defaults from within the BIOS if you are not comfortable with clearing the CMOS.
Sometimes installation errors can be down to faulty RAM or Hard Disk, so I would run MemTest86 or Windows Memory Diagnostic, and also the disk diagnostics from your hard drive manufacturer.
Another thing to make sure is that your Hard drives are set to IDE mode in case you have some kind of incompatibility or you don't have a driver disc.