Non-Asus X58 PC affected.
My 2-generation-old PC (now my wife's) had the same issue. (As old as it is, it's surprising how good of a machine it still is.)
i920 3.6 GHz OC
ASRock X58 Extreme
BIOS P2.90 (last update, 2011)
Boot Device Adata SX900 (256 GB) SSD
6GB Triple-Channel (remember that?) RAM 667 GHz XMP
AMD R9 280
Would hang on Windows logo on the 1803 update until VT-d switched off. Since I'm not running any VMs on that system I can just leave it off.
BTW, Hyper-V is disabled. I thought at first that since VT-d is for VM and Hyper-V is enabled by default on a clean installation (I believe) that it might be an issue but this PC was upgraded and it wasn't on.
I wasted several hours on this before discovering the VT-d fix. Don't you love being a de facto Unpaid Windows Beta Tester?
Microsoft needs to hot-fix this.