There are no drivers supported by Acer for Windows 7 and this system.
That is fine, I am aware of that as when I checked their website I realized it is only for windows 10 no windows 7
But I am still interested to do install windows 7, but I am stuck at the point where external USB pen drive or external USB CD ROM can't pass the error message
A required CD/DVD drive device driver is missing
and cause is
In order to resolve this you need to download the appropriate RAID drivers for your computer's motherboard. If you know the manufacturer of your motherboard you can usually get these from their website or a disk that came with your motherboard or PC.
Based on the this website