boot - Why can't I see my USB drive during Windows 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 comments 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.

Specs:

• Mobo: ASUS Z170-A


• CPU: Core i7 6700k


• RAM: 2 ✕ 8GB DDR4 2666Hz Hyper X Fury


• SSD: Samsung 950 Pro NVMe M.2.

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

Answer

Your motherboard does not have any EHCI (USB 2.0) controllers. Intel decided to give those up with the 100-series chipsets. So you have only XHCI (USB 3.0) which Windows 7 knows nothing about.

The only reason why you are able to boot to Windows 7 Installation on USB Key is because your PC's BIOS is emulating a hard-drive/CD-ROM from it! Neat trick, but it doesn't always get you through to the end of a Windows 7 install.

ANYWAY, lets think outside the box... why are you doing any of this via USB Key? Please tell me you have DVD/Bluray drive on this PC.

If so, you could always burn the NVMe drivers to a blank DVD. Then you can install Windows 7 off the Win7 DVD. When you get to the "load driver" bit you can eject the Win7 DVD and insert your NVMe DVD. Once the driver has loaded, you can eject the NVMe DVD and re-insert the Win7 DVD to finish the install.

While you're at it you could also put all other drivers (ethernet, audio, graphics, usb3) on the NVMe DVD so you can get Win7 internet-connected and ready for Windows Updates. Beware that the first scan of Windows Updates on a fresh install might take 3~4 hours (I'm not kidding).