Windows 10 Feature Update 2004 taking too long to install

I'm still here...still not able to complete the update (now on attempt 27, maybe more). I successfully ported my physical system over to a virtual machine, removed all non-Microsoft tools and drivers that are no longer relevant in its virtual state and still, same failures in that environment. This confirms it's not hardware! My physical system still runs/operates without problems as does the identical virtual system. The only good news is the failure results are much quicker now in the virtual world. Still the same ole boring Update Failed (nothing but a dialog box indicating such), but now it only takes 45 minutes. I've reviewed the setuperr.log (among the many, many others), cleaning it out prior to every attempt, and still get nothing out of the process that provides even a hint of where the problem is or what caused the "failure".

Such a shame this product, as much as it sucks, isn't a vacuum (new business opportunity for Microsoft?).

On to attempt 28!

Intel i5, 3.8GHz; 16GB RAM; 1 TB SSD, about half used.

Yea, not buying that it's the fault of "the system."

Admittedly, it's hard to design something that works smoothly on as many different systems and on as many different software setups, but after 3.5 months, one would like to think that the update process would be a bit less rocky. 

Good news: I'm at 82%. 

Bad news: it has been at 82% for about an hour.

Thank God for day drinking.

I'm having the same issue, only a few months later.

I was informed that an update was available (which routinely happens mid month) and without too much concern began the update process.

The machine presumably had to reboot to complete the install, and after about 20 min I was at a blue screen with the notice that it was updating. 4+ hours later, the screen hadn't changed. It would be nice if MS had bothered to put some sort of percent update status, but nothing except an endlessly spiraling circle.

I assumed that the install had stalled, which has happened in the past (gee, thanks Microsoft), so I did a hard reboot. That resulted in a black screen with the line "undoing changes." 3+ hours later, it finally came up to the desktop, but everything was glacially slow. I clicked on settings (waited 10+ min), clicked on updates (waited 10+ min) and saw an update status of "installing - 23%."

I though this a bit reassuring, so I went to bed, certain that by morning all would be well.

Morning.

Things are kinda working -- my off-line backup apparently worked without issue -- but that 23% had only crept up to 52% in 6 hours. Now, close to 20 hours in, and it's only at 75%.

Over the decades, I've fought through myriad updates. I was there in the DOS days and when Windows 3 (3.1) became Windows 95. But this latest has been the worst. 

Who needs a computer virus when you have Windows?

LOL! "Who needs a virus...", that's the best one yet. 

I am hearing this stuff, and it's chilling. It makes no sense that there are so many people with this 'slow update install' issue. Then there are others, like me, who've been getting them done in minutes. I have had only two customers, so far, that have had perpetual installs that had to be stopped. But I was able to get them done in, the longest, two hours. I just don't get it. And I'm not getting much from the Insider support group that is helpful. It seems too many wanna blame the system. I'm not buying that, unless, of course, MS is going into the hardware business!!!

I'm having the same issue, only a few months later.

I was informed that an update was available (which routinely happens mid month) and without too much concern began the update process.

The machine presumably had to reboot to complete the install, and after about 20 min I was at a blue screen with the notice that it was updating. 4+ hours later, the screen hadn't changed. It would be nice if MS had bothered to put some sort of percent update status, but nothing except an endlessly spiraling circle.

I assumed that the install had stalled, which has happened in the past (gee, thanks Microsoft), so I did a hard reboot. That resulted in a black screen with the line "undoing changes." 3+ hours later, it finally came up to the desktop, but everything was glacially slow. I clicked on settings (waited 10+ min), clicked on updates (waited 10+ min) and saw an update status of "installing - 23%."

I though this a bit reassuring, so I went to bed, certain that by morning all would be well.

Morning.

Things are kinda working -- my off-line backup apparently worked without issue -- but that 23% had only crept up to 52% in 6 hours. Now, close to 20 hours in, and it's only at 75%.

Over the decades, I've fought through myriad updates. I was there in the DOS days and when Windows 3 (3.1) became Windows 95. But this latest has been the worst. 

Who needs a computer virus when you have Windows?

I am an independent PC support specialist and my clients are getting it rolled out to them.  One of my machines was asking me to install it or set a date and time.  The average time from saying yes to ready to use again is around 6 hours.  That time is not any faster on a brand new computer with 9th generation Core I-7 4ghz, with 1TB PCIE NvME SSD and 32gb of RAM.

For a giggle, I asked Google how long it takes to install the May 2004 Update which is now being called "Feature update to Windows 10, version 20H2" and Google's pleasant voice read off part of an article saying it takes about twenty minutes.  I giggled all right and that is how I wound up here.  I just wanted to toss in my experience with it on the 15 or so computers I have actually witnessed hands-on do it.  A few of those I was called in after it failed  It seems to install more successfully on custom-built machines than the name brand store-bought machines from the big manufacturers.  That is just my observation so far.  My laptop took it fine and it is one of those brand names we all know.  But it did take about 6 hours.

As an "Insider" I get these updates before the public, or so I'm told. The GOOGLE time you mentioned, is longer than any of the 20H2 updates have taken. There has been 4 or more, and the longest time it took for the update was 13 minutes. I'm at 20211.1000 release. I did build my rig. I have an AMD Ryzen 5 CPU, that boosts up to 4.2Ghz. I have a 2TB NAND WD M.2 SSD, with 32GB RAM. An MSI Radeon RX 570 DirectX 12 RX 570 ARMOR 8G OCGPU.

I'm not sure why this thing is so buggy, and my "Insider" tag has gotten me no closer to a solution as anybody else. But 6 hours! Man!....