0xc1900201 error installing Windows 10

Last Updated on September 14, 2018 by Dave Farquhar

Are you getting a 0xc1900201 error installing Windows 10? I got both that and 0xc1900200. Here’s how I fixed it.

I upgraded my venerable Dell E1505 to Windows 10 over the weekend. It was harder than it needed to be, but I got it running. It’s an old machine, but for some tasks, it can handle Windows 10.

Here’s how I got the Windows 10 install working.

Error codes 0xc1900201 and 0xc1900200

Clicking the Windows 10 upgrade icon in my system tray failed. I got the message to the right, which made me speculate about Microsoft’s recreational drug use. My Dell had an older Intel CPU, but it was a mainstream Intel, and it met the minimum requirements.

I tried several workarounds, including downloading the ISO file and trying to use the Media Creation Tool. Whether I did that or tried the easier update to Windows method, I got the same results. Each time the upgrade appeared to work, then would fail 45 minutes in with error codes 0xc1900200 or 0xc1900201. Neither error code is well documented, although one of the messages told me my CPU lacks the NX or XD feature. I vaguely remembered this machine having a BIOS feature to enable or disable that.

I went into the BIOS to make sure the feature was enabled. It was. It’s in the section called CPU Security on a Dell E1505. Its location on other older machines will vary, particularly on non-Dell machines.

The solution

To fix this, I had to dig into the registry. Here’s the workaround that finally got those error messages gone and let me continue:

1. Open Regedit as an Administrator;
2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate
3. If it does not already exist, create a key called OSUpgrade
4. Open the key
5. Create a new DWORD called AllowOSUpgrade with the value of 1. If AllowOSUpgrade already exists, make sure its value is 1. 
6. Once complete close Regedit.

In my case, the registry entry was already there, but was set to 0.

I’m not sure if the problem was the age of my machine, or if I made it harder on myself by having run a tool a few months ago that stopped the Windows 10 upgrade from happening automatically. The author of that tool isn’t forthcoming about the changes the tool makes, nor about whether it also interferes with manual upgrades. I suspect the latter, as I’ve upgraded other aged machines to Windows 10. I honestly don’t know where else that registry key would have come from.

I think the most likely scenario was that I ran a tool to block the automatic upgrade so it would happen when I triggered it, not when Microsoft decided to push out a round of updates. And that I didn’t realize the tool would interfere with a manual update. It’s highly likely that other people did the same thing I did, and rushed to disable Windows 10’s automatic updates without understanding the same trick would interfere with manual updates.

I learned the hard way. And now I’ve told you.

Windows 10 and older computers

A lot of people tell you not to bother trying to install Windows 10 on a machine with error codes like 0xc1900200, saying that’s the machine’s way of saying it’s too old. That’s not how I roll. As long as you put an SSD in these older machines, they can still be useful. Install the new operating system, optimize it, and put the machine back to work. If it doesn’t have enough power, try Chrome OS on it as a fallback option.

Windows 10 does have a lot of features, especially security features, that rely on newer CPUs and chipsets. But it will still run on the older machines, just not with the enhanced security. It still works, and it’s still more secure than Windows 7 would be, and considerably more secure than Vista or XP.

It’s also possible that a clean install would have worked. Usually a clean install gives fewer complications than an upgrade. A clean install definitely does run faster than an upgrade install. But I wanted to see what would happen, and now we know. Doing an upgrade does let you get the system up and running on the new version a lot faster.

I’d prefer the upgrade to be hassle free. But I do think Windows 10 has some worthwhile advantages.  So I recommend it.