I agree it would be nice to know which diskpart command you ran. If you ran "list disk" and didn't see the drive at all, then you might need the Intel Rapid Storage driver. For your purposes, get the appropriate "F6Flpy.zip" version based on whether you're trying to use 32-bit or 64-bit Windows; I certainly recommend the latter: https://downloadcenter.intel.com/download/27400/Intel-Rapid-Storage-Technology-Intel-RST-User-Interf...
Follow-up note to the above: Do you intend to install Windows 7 alongside Linux, or replace the Linux installation? If the former, Windows 7 might end up clobbering the Linux bootloader, so be prepared to do some work to get that working again and then to use a Linux bootloader to provide an option to boot into Windows. If the latter, I would use the diskpart "clean" command to mark the entire disk as empty before proceeding rather than just deleting partitions, then click the "Refresh" button in the wizard step that allows you choose where to install Windows after running that command.
Getting Windows 7 to run on this system - though it is possible -- will require building a customized install image. This is a Haswell refresh/Braswell platform system - for which native installers do not exist that support the USB 3.0 chipset in the system.
This is a major undertaking -- if you want to make this work, see the link below. It will take considerable effort and time to build an image that will install.
If the interface of 10 is the issue, just install 10 and a copy of Classic Shell, which will allow you to place most of the Windows 7 interface atop Windows 7. It'll be one major leap easier to do than what's involved in building a 7 install image for this system.
If you still must install 7, follow the procedure here (for Braswell and Skylake)
@ejn63the OP already mentioned that the issue was that Windows 10's assistive technology wasn't quite there for this user's needs and that the USB 3.0 drivers are injected, which is also indicated by the fact that he's getting all the way to the step where you choose where to install Windows. On systems that don't support USB xHCI controllers and therefore require the custom build you're talking about, they see an error about missing DVD drivers or something at the very beginning of the wizard.
There are a number of updates and hotfixes that must be slipped into the installation media -- not just the USB drivers. That's why a completely new image needs to be built for this to work with this chipset.
The diskpart command I ran was list disk. The only output I got was the 8 gig USB stick I am using to install Windows from. I have tried three different versions of Intel's Rapid Storage driver. The latest (15.9 I think), 14.8 and 12.9. With each driver, I have the 64-bit floppies in separate folders on the USB stick. When I hit load driver and browse to these locations, none of them will allow me to click next, assuming no compatible driver found. As far as Linux, it is not installed on the drive, but is being run from a live Ubuntu Mate USB image. Any other ideas? I'm open to any you can think of, I am truly stumped here.
Thanks much in advance,
Guy (Stumped in Ohio)
Here's something else I think is weird. When booted into Ubuntu, I cannot see the drive by issuing such commands as lspci, or lshw -class storage. I do see it in gparted though as /dev/blcm0, not /dev/sda like I'm normally used to seeing. I am able to create a blank partition table in gparted though, and a bootable ntfs partition which I can then mount. Does this have anything to do with my Windows issue? Again, thanks much in advance.
Guy (Stumped in Ohio)