Well this is a nice surprise. Well done Microsoft...
(note: previously posted on the Reddit Windows 10 sub, and the Windows 10 forum)
I have an old Lenovo ThinkCentre desktop computer model M58 7483 that I use to run legacy hardware/peripherals/software that require a serial port that modern motherboards/computers no longer have.
When I got the computer about a month ago it had an early version of Windows 10 64bit (15xx) installed.
WU said it could be updated to 1803 but not 1809. It took 7+ hours to update to 1803, and WU said it was a targeted update for 1809.
Today when I turned it on, and checked to see if there were any updates available on WU it said 1809 could now be downloaded and installed.
I let the update proceed, and it completed successfully in just over 2 hours, and haven't found any issues at all so far.
All the legacy hardware and motherboard serial port are working properly after the update to 1809.
I didn't expect it to be able to install/run 1803 let alone 1809 when I got it, and was even considering downgrading to Windows 7.
The computer only has 4 GB of DDR3 ram, but 1809 is only using about 2.5 GB, leaving up to 1.5 GB free.
The Speccy profile for the computer are, after the update:
Operating System: Windows 10 Pro 64-bit 1809
Computer type: Desktop
Installation Date: 7/02/2019 12:57:13 PM
CPU: Intel Core 2 Duo E8400 @ 3.00GHz 48 °C
Wolfdale 45nm Technology
RAM: 4.00GB Dual-Channel DDR3 @ 532MHz (7-7-7-20)
Motherboard: LENOVO (LGA 775)
Graphics: 24MB37 (1920x1080@60Hz)
Intel Q45/Q43 Express Chipset (Lenovo)
Storage: 596GB Western Digital WDC WD6400AAKS-00A7B2 (SATA ) 47 °C
Optical Drives: HL-DT-ST DVD-RAM GH40N
Audio: High Definition Audio Device