You want to download the .ISO file of the exact version of Windows 7 that originally shipped with your G73 so you can activate it with the Windows 7 Product Key on the label on the bottom of the laptop. But any Windows 7 .ISO file should install the Windows Plug-n-Play drivers necessary for a working installation. They would only fail to activate without a valid Product Key.
When you receive an error that the chipset. driver cannot be found, it is more likely symptomatic of a bad burn or a failure of your ODD to read the disk. One resolution to this problem is to burn the installation disk again at a slower speed. You may even wish to reboot prior to the re attempt and make sure Antivirus is disabled and no other applications are running.
You could also try a different brand of DVD or choose to burn the file to a USB flash drive.
However,you could possibly have a problem with your ODD reading discs since you also reported an error when attempting an ASUS Factory Restore from disk. Cleaning the laser lenses of your ODD may also improve disk read performance.
G74SX-A1 - stock hardware - BIOS 202 - 2nd Monitor VISIO VF551XVT