Upgrading Server 2016 to 2019

I have a physical Dell T320 that I'm trying to upgrade to 2019. It is an in place upgrade. I've tried the options with and without doing updates first, and it still fails. I've also tried pulling the network cable.

The failure code is 0xC1900101 - 0x40017

Windows updates are current. Drivers/firmware is current, and there is 35GB+ free on the C drive.

As Michael Hampton points out, you probably have a driver or a piece of software installed that is incompatible with Server 2019. Given the age of the T320 it may not be possible to find 2019-compatible drivers.

We've seen this before on 2019 upgrades. Ours were Intel NVMe storage drivers (dated 2016) and getting 2019-compatible drivers from Intel was like getting blood out of a stone (but eventually we did get them).

Your first step though is to make sure that every driver and piece of software you have is up to date, and then trying again. However, given the age of the T320 you may have limited success.

You state that everything on firmware and drivers and Windows updates are current. If you have an antivirus or some other piece of integral software that also cannot be updated any further, this may just spell the end of the road for Windows upgrades for that server.