One drive, no attached devices, system not ready for 1903

[Zanzibar2Far]

As per title any ideas, system as follows (Intel report);

Computer
ASRock Z97M-ITX/ac
Operating System
Microsoft Windows 10 Pro (64-bit)
Processor
Intel® Core™ i5-4690K CPU @ 3.50GHz
Chipset
Intel® 9 Series Chipset Family
Graphics
NVIDIA GeForce GTX 1060 6GB
Audio
NVIDIA High Definition Audio
NVIDIA Virtual Audio Device (Wave Extensible) (WDM)
Realtek High Definition Audio
Networking and I/O
Realtek 8821AE Wireless LAN 802.11ac PCI-E NIC
Qualcomm Atheros AR8171/8175 PCI-E Gigabit Ethernet Controller (NDIS 6.30)
Memory
16 GB
Storage
SanDisk Ultra II 960GB

Intel claims no updates
available.

 

[Zanzibar2Far]

Do you mean that Windows Update isn't offering it?

I don't think Pro machines are being offered it via update checker yet, I downloaded the update assistant. 2 of my other Haswell boxes have installed it without issue. Basically I'm getting the not ready for 1903 at this time, but no indication of what driver/part is the issue.