I get this when i try to install the gpu drivers when using a onboard gpu, sounds like something is not being done right
Going to assume that you have a system drive where you install windows 7 sp1
in that case, do a fresh install of win 7 and the software listed under each section and in this general order from this page:
http://www.asus.com/Motherboards/Intel_Socket_1155/SABERTOOTH_Z77/#download
BIOS
try installing 1504, pretty stable so far from me and never hurts to be up to date
Chipset
Intel(R) Chipset Software Installation Utility V9.3.0.1019 for Windows XP/7/8 32bit & 64bit.(WHQL)
SATA
Intel(R) Rapid Storage Technology Driver Software V11.1.0.1006 for Windows XP/7 32bit & 64bit.(WHQL)
Asmedia SATA Controller Driver V1.3.4.0 for Windows XP 32bit & XP 64bit & Win7 32bit & Win7 64bit.(WHQL)
USB
Intel(R) USB 3.0 Controller Driver V1.0.5.235 for Windows 7 32bit & 64bit.(WHQL)
Asmedia USB 3.0 Driver V1.14.3.0 for Windows XP 32bit & XP 64bit & Win7 32bit & Win7 64bit.(WHQL)
LAN
Intel LAN Driver V17.1.0.0 for Windows XP 32bit & XP 64bit & Win7 32bit & Win7 64bit.(WHQL)
Audio
Realtek Audio Driver V5.10.0.6657 for Windows XP 32bit & 64bit.(WHQL)
Utilities
ASUS AI Suite II V1.04.04
(deselect everything but Thermal Radar, or pick the ones you actually want)
Can't give you direct links since the page is bit stalin, but that worked great every time i had to do a reformat of my win7 system
If you run into problems, at what step do you do so? Could you get us a screencap of the error message?