ppippus - Welcome to the Windows 7 Forums Website!
To install Windows 7, you don't need a secondary program such as NLite.
Are you installing on a RAID or AHCI-enabled hard drive? If so just load the drivers during the install process when you get to the screen which shows the hard drives.
As TM stated, just make sure you have the latest Windows 7 drivers from the Asus website for your model of motherboard.