cd/dvd drive driver missing while installing windows 7 in inspiron 3162 (win 10, 500 gb, 4gb)

Some software I previously bought only works in windows 7.

As the latest version of that software is costly, I decided to install windows 7 in by Inspiron 3162 (Pentium 3700, Windows 10 home, 500 gb hdd, 4gb ram).

Copied the original windows 7 to boot-able USB Flash drive.

Tried to install... boot from USB drive....

struck in the screen showing

CD/DVD driver device driver is missing...

Tried steps

- change usb port

- formatted USB drive and rewrite windows 7

- downloaded some drivers said in some forums and tried to install

- try to change bios. - no option of changing usb 3 or AHCI to any other

Please help