Follow this procedure:
1. Download Intel driver for NVMe SSD from the following link:
Consumer SSD | Download | Samsung V-NAND SSD
2. Extract the driver from the zip file to Samsung NVMe Driver directory .
3. Copy Samsung NVMe Driver directory to your USB stick with WIN7 installation.
4. During Win 7 installation, while windows will inform you that the driver is missing, browse to the Samsung NVMe Driver directory, windows will install the NVMe driver.
5. Continue with installation.
Since the link to driver was for driver installer rather then to the driver itself, I've uploaded for you the driver files. You can download from the following link:
I've used this in my installation.