Why can't I see my usb drive during win 7 installation?

I'm trying to install Windows 7 professional SP1 64 bits on a NVMe SSD from a USB drive. I know Windows 7 does not have NVMe support so I need to install the drivers during the installation. The problem is that during the installation I cannot see my usb drive were I copied the drivers. Here is what I did:

1. I used the rufus tool to create a bootable usb in GPT partition UEFI mode FAT32 format.
2. I added the drivers to the usb and to a second usb.
3. I inserted the usb in the computer's usb 2.0 port and entered the BIOS.
4. on the BIOS I enabled CSM support and selected UEFI mode for Storage and PCIe.
5. Then I booted into the installer and it asked me for a driver which I was expecting.
6. I clicked on Browse and I could only see the X: drive which has the installation but I couldn't see my usb drive.
7. I inserted my second usb but that didn't work either. I read Idea of people inserting it on the usb 3.0 slot and that why it didn't recognize it, but that isn't the case here, I'm using usb 2.0.

These are my system specs:

MOBO: Asus Z170-A CPU: core i7 6700k RAM: 2 x 8GB DDR4 2666Hz Hyper X Fury SSD: Samsung 950 Pro NVMe M.2.

I might be missin something in the BIOS but I don't know what.

Please help me.

Thanks.

Recent Questions...