This is the NUC7i3DNHE:
It comes with the i3-7100U processor.
It supports Windows 10, 64-bit*, Windows 10 IoT Enterprise*, Windows Server 2016*
It does not come with the OS.
It is a kit, and does not come with memory or storage, or the OS.
If you want Windows 10 IOT Enterprise,you must purchase it.
However if you buy NUC7i3DNHNC you will get HDD kit with power adapter, 1TB HDD, 4GB DDR4 SDRAM, Windows 10 64 bit PRO. If you will buy NUC7i3DNKTC you get kit with power adapter, Intel 128 GB NVMe SSD, 4GB DDR4 SDRAM, Windows 10 64 bit PRO. Please refer to Technical Product Specification: https://www.intel.com/content/dam/support/us/en/documents/mini-pcs/nuc-kits/NUC7i3DN_TechProdSpec.pdf
You may upgrade both option later with additional SDRAM. In the first option (NUC7i3DNHNC), you may add also SSD and migrate your Windows from the HDD to SSD.
Of course, you may chose the NUC7i3DNHE and add the drives, memory and Windows.