I've created a 2m35s desktop video showing a boot of stock 18.04 and 19.10 on my system, posted at https://chaetura.net/ms-vid1-bug-1848534.webm (18MB, renders in Chrome window for me, or use VLC to watch). I've posted a second video showing the shortcut to boot 19.10 quickly that I described earlier, but which I have simplified to simply pulling the plug with "power off" from Hyper-V at the grub menu, do not close the Connection window, restart, and 19.10 will boot fast. Note that "system setup" (I previously mistakenly wrote "system startup") doesn't appear in the grub menu of stock 19.10; it appears only after updating packages in Ubuntu. Yes, I am able to select the “restart” button with the keyboard. But then the shortcut doesn’t work; what triggers the shortcut is powering off the VM. https://chaetura.net/ms-vid2-bug-1848534.webm Furthermore, the shortcut boot of 19.10 solves *THREE* significant problems with stock 19.10 that are not problems with stock 18.04.3. Reasonable conclusion is that all three problems have the same cause, which somehow the shortcut boot avoids: 1) avoids the long delay in startup 2) allows user to select any screen size for the Connection (whereas stock 19.10 came in one size only and user has no opportunity to select; goes hand in hand with the different login screen, as you can see in video. 3) after login, cut-and-paste from guest to host is possible. Not functional with stock 19.10. I see that graphical artifact at some point during boot of any Ubuntu VM in Hyper-V. You can see it in the video too. In 19.10 it comes while the Spectre mitigation message is on the screen in console, at a point where console changes its rendering/mode somehow and the message reappears in a slightly different font. I forgot to show /proc/cmdline and "uname -a" in the video but for 19.10 it is: BOOT_IMAGE=/boot/vmlinuz-5.3.0-23-generic root=PARTUUID=[blahblah] ro quiet splash Linux stock19 5.3.0-23-generic #25-Ubuntu SMP Tue Nov 12 09:22:33 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux and in 18.04.3 it is BOOT_IMAGE=/boot/vmlinuz-5.0.0-25-generic root=LABEL=desktop-rootfs ro quiet splash vt.handoff=1 Linux stock18 5.0.0-25-generic #26~18.04.1-Ubuntu SMP Thu Aug 1 13:51:02 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux Note that I installed my 19.10 via Hyper-V Manager's "quick-create" rather than from an .iso downloaded separately. Same kernel version, but mine is an earlier packaging number, and who knows what else may be different about the install image. The manager says the image was updated 17 October 2019. The Manager downloads a zip file from partner-images.canonical.com via https so I cannot snoop the URL looking at the packets. I have a copy of the .vhdx which is insie the zip file, and I'm messing around with trying to mount it in another VM but I haven't solved that yet. My Windows 10 Pro x64 build (today) is Win10: Version 1909 (OS Build 18363.778). No further windows updates are available, and I don't understand Windows version numbers, so I can't explain the discrepancy from yours. The startup delay persists after updating the stock install of 19.10 (using aptitude; all available updates accepted but the grub packages held back till I learn how to do them; they broke my last install). I noticed while making the video that during the long startup delay, the process is using GPU at 5% -- significant amount of usage (documented in video). Therefore I've included my GPU information at bottom below. I boot stock quick-create 19.10. I change the name of the VM only ("Stock19"). Default ethernet adapter. Note that the first boot is immediate; the only one that will ever be that fast, unless I go through the shortcut boot sequence. On first boot, I go through Ubuntu configuration screens minimally. Post-install runs. No further updates, just reboot now (because critical-chain timings are much longer the first boot than all subsequent boots). Login, run terminal, sudo-i, then systemd-analyze critical-chain: first line is: graphical.target @1min 44.651s This is typical of all subsequent boots. I'm not copying the full output all because cut-and-paste text from guest to host is broken for me in 19.10. It is not broken in an 18.04.3 guest ("updated 19 August 2019" in Hyper-V Manager). Here for comparison is the critical-chain for 18.04, which I can cut-and-paste. Less than 2s to "graphical.target", compared with 104s for 19.10. swift@Riflebird:~$ sudo -i [sudo] password for swift: root@Riflebird:~# systemd-analyze critical-chain The time after the unit is active or started is printed after the "@" character. The time the unit takes to start is printed after the "+" character. graphical.target @1.836s └─multi-user.target @1.836s └─kerneloops.service @1.829s +6ms └─network-online.target @1.827s └─NetworkManager-wait-online.service @663ms +1.163s └─NetworkManager.service @566ms +96ms └─dbus.service @538ms └─basic.target @532ms └─sockets.target @532ms └─snapd.socket @530ms +2ms └─sysinit.target @529ms └─apparmor.service @397ms +132ms └─local-fs.target @395ms └─run-user-121.mount @807ms └─local-fs-pre.target @191ms └─keyboard-setup.service @134ms +57ms └─systemd-journald.socket @127ms └─system.slice @127ms └─-.slice @125ms root@Riflebird:~# GPU Information: NVIDIA System Information report created on: 04/19/2020 21:14:21 System name: QUISCALUS [Display] Operating System: Windows 10 Pro, 64-bit DirectX version: 12.0 GPU processor: GeForce GTX 1050 Ti Driver version: 445.75 Driver Type: DCH Direct3D API version: 12 Direct3D feature level: 12_1 CUDA Cores: 768 Core clock: 1354 MHz Memory data rate: 7.01 Gbps Memory interface: 128-bit Memory bandwidth: 112.13 GB/s Total available graphics memory: 20444 MB Dedicated video memory: 4096 MB GDDR5 System video memory: 0 MB Shared system memory: 16348 MB Video BIOS version: 86.07.39.80.63 IRQ: Not used Bus: PCI Express x16 Gen3 Device Id: 10DE 1C82 33511462 Part Number: G210 0000 [Components] nvui.dll 8.17.14.4575 NVIDIA User Experience Driver Component nvxdplcy.dll 8.17.14.4575 NVIDIA User Experience Driver Component nvxdbat.dll 8.17.14.4575 NVIDIA User Experience Driver Component nvxdapix.dll 8.17.14.4575 NVIDIA User Experience Driver Component NVCPL.DLL 8.17.14.4575 NVIDIA User Experience Driver Component nvCplUIR.dll 8.1.940.0 NVIDIA Control Panel nvCplUI.exe 8.1.940.0 NVIDIA Control Panel nvWSSR.dll 26.21.14.4575 NVIDIA Workstation Server nvWSS.dll 26.21.14.4575 NVIDIA Workstation Server nvViTvSR.dll 26.21.14.4575 NVIDIA Video Server nvViTvS.dll 26.21.14.4575 NVIDIA Video Server nvLicensingS.dll 6.14.14.4575 NVIDIA Licensing Server nvDevToolS.dll 26.21.14.4575 NVIDIA 3D Settings Server nvDispSR.dll 26.21.14.4575 NVIDIA Display Server nvDispS.dll 26.21.14.4575 NVIDIA Display Server PhysX 09.19.0218 NVIDIA PhysX NVCUDA.DLL 26.21.14.4575 NVIDIA CUDA 11.0.126 driver nvGameSR.dll 26.21.14.4575 NVIDIA 3D Settings Server nvGameS.dll 26.21.14.4575 NVIDIA 3D Settings Server