Windows Booting very slow after 2004 update ,

@AFWS 

As for performance issues during normal working (post 2004 update), it can be beneficial to stop and disable the SYSMAIN, and Windows Search services.

Is the Windows Search the same as the "Indexing Service" mentioned in previous replies. I looked for a Indexing Service ,but doesn't appear to be one. I got the SysMain and Windows Search now disabled.

Whatever was taking all day for a 'Restart' (not shutting down or booting back up again) has disappeared for me. Actually, the problem disappeared before the latest update so what that was all about is beyond me! But the slow 'Restart' (the circle just turning and turning and turning before the Restart would disappear) has done just that ... disappeared!

@AFWS I assume the GTX950M is for an external monitor, as you have disabled it?

Anyway, on a related post, a user with Gigabyte X570 motherboard found that in the BIOS, turning off the SATA HOTPLUG made his reboot time issue much better. NOTE: that might only apply to certain motherboard types, and must NOT be done if you have set up an active disk RAID configuration.

As for performance issues during normal working (post 2004 update), it can be beneficial to stop and disable the SYSMAIN, and Windows Search services.

Leave it to a Windows update to screw something up. I didn't install the 1909 update ,but installed 2004 on 6/05. Noticed a couple weeks ago it took longer to boot ,but didn't think nothing about it. Restarted my laptop yesterday just to check and it was still slow. I timed it today and it took 11 minutes and 32 seconds to go from the Windows/HP logo screen to the user sign in screen. You add the "Restarting" screen and after sign in and it would take like 15 minutes for a restart. Before the 2004 update and it was nowhere close to that long. I tried these things recommended online and nothing has fixed it.

1: Make sure latest drivers for GTX 950M and Intel 530 Graphics

2: Disable startup programs

3: Install trial version of Malwarebytes and scanned(Came back clean)

4: Disabled GTX 950M Graphics

5: Turned off "Fast Startup" in power settings.

6: Tweaked "Performance" settings

7: sfc /scannow

8: Defragment

@Sumit - while I am sure you are correct, that Feature Update 2004 is immature, these sorts of problems arising NOW is surely a reflection of insufficient testing and not using more diverse configurations., on the part of Microsoft. I know that certain Realtek Drivers  are causing issues, and that it is on hold for some configurations. Also the "Storage Devices" bug can stop the upgrade being offered. The printer issues were a commonly reported issue too, although it HAS had a fix.  Certain NVIDIA display drivers are also an issue. Those too should have stopped any install being offered.

Although it seems that Microsoft IS liaising with the major companies like NVIDIA, Realtek etc. you seem to be suggesting that there are many more problem drivers out there, that can cause performance issues.

Again, this comes back to insufficient testing of the diverse brands and config that can exist. Surely a company as large as Microsoft, MUST have some sort of verification "checklist" to go through (covering all the manufacturers and driver error classes and scenarios they had with prior upgrades and updates) before "passing" a big update like this as safe to RTM?

Most of what is being reported on here, are related to performance, but many of the driver related issues (AFAIK) are causing stuff to fail, rather than perform badly. My gut-feel for these issues, is that it is a complex interaction between the internal MS system services, since the "redesign" of search, to try to cut back on the Cortana integration, and some system are suffering because certain internal functions are fighting for resources when they should not be.

On a related note, I would really like the "AskPerf" MS blog/group to be more interactive on these performance issues, but I suspect not enough users know about  it to get the traction it needs. See:

https://techcommunity.microsoft.com/t5/ask-the-performance-team/welcome-back-askperf/ba-p/386881