Windows Booting very slow after 2004 update ,

Here is what worked for me after the Windows 10 2004 update made two of my computers run as slow as molasses.

(1) Boot in Safe Mode

(2) Delete everything in the Windows prefetch folder.  The folder is usually at C:\Windows\Prefetch

(3) Reboot

Windows rebuilds the prefetch folder so deleting it will not do any harm.  However, if you feel squeamish about deleting it, then rename it and create a new, empty prefetch folder in its place.

I spent hours on the first computer before stumbling onto this.  When the Windows update, and slowness, hit the second computer I tried this fix first and it immediately sped up.

Hopefully, it will help you.

Hi, the problem seems to be HDD related, on 2 desktop PCs and one laptop, I have Windows of one desktop PC and the laptop on SSD, and the other desktop PC on HDD. The HDD desktop is slightly more powerful than the laptop but way less powerful than the ssd desktop. On both ssd systems boot load times and operations were mostly unaffected by the update. On the HDD desktop, it's now taking up to 5 minutes instead of 30-50 seconds to completely load everything on boot after the 2004 update. while loading everything while being booted up my HDD now sits at 100% and everything takes forever to load. SSDs are cheap enough now, my advice would just to get 1 120Gb or 240Gb ssd (even sata ones are fine) and to keep your hdd as more storage. Windows has moved on from being installed on HDD.

I running a laptop with single hard drive bay - in order to upgrade I would need to buy a 1TB SSD hard drive, which I cannot afford to do this year. 

Basically, tough luck from Microsoft.

Windows isn't becoming slower. That's a misconception !

I'm a programmer and I had (and still have) Windows 10 from it's first release. I've gone through all the updates and versions and the system kept it's parameters without exceptions.

Now I've installed v 2004, It's a fresh install because lately I've done some experiments with my PC and .... you get the picture.

The system has the same speed, with a slightly noticeable "pause" when you start a program or app than the 1909.

If you're still running on HDD, please change it immediately with an SSD.

Two things I've always done, right after a fresh install or major update of Windows:

1. Stopped and disabled SysMain service, or SuperFetch how it was called in early versions.
2. Stopped and disabled indexing service.

As a professional, I've never understood the role of SuperFetch (SysMain), other than keeping my drive bussy all the time. And the indexing service is just lame. I mean, if I don't know to organize and label my stuff it's my problem. That's my point of view, anyway.

Right after stopping SysMain, you drive will breath again. Trust me on this one.

It does work for me but only for one day, following start up , boot time is back to 50 seconds. I am using western digital green ssd Ryzen 3 2200g with 16gb ram

My PC now takes more than three times as long to boot up as prior to the update (also now a bit slower to shut down) . . . but then it seems to perform pretty much as per normal (for Win 10 that is).  But that's the very least of the problems that, sadly, I daily experience with Win 10 (MS's absolute worst operating system ever!).