This guide should fix the issue with igdkmd64.sys and a BSOD

Update (11/27/2019)

This issue has yet to be resolved in Windows LTSC (Build 1809)

I’m a tech, and in this environment we use Apple’s excellent iMacs with Windows and macOS. The 2011 model is the last of the thick, optical drive-equipped and easily serviceable iMac series. They came in a 21.5″ and 27″ model. RAM, disks, and display are pretty easy to install.

Under Windows 10, booting from a USB stick into a UEFI mode, Bootcamp 5.1 drivers install and work correctly but sound from the onboard Cirrus Logic WILL NOT WORK.

The biggest issue, however, is that Windows immediately grabs an “updated” Intel Graphics driver, installs it, and then blue-screens. One or two reboots will happen, upon which Windows will start up the System Repair. This is where we can easily fix this particular issue.

Note that these iMacs have two video cards onboard. They’ll have the integrated Intel graphics and some version of an AMD Radeon. We’re disabling the Intel graphics, which won’t affect the use of the iMac, which primarily runs on the Radeon under normal circumstances.

Navigate through the options until you’re allowed to boot with options, at which point Safe Mode or Safe Mode with Networking is the choice needed. Boot into Windows 10, log in, and open the Device Manager.

You’ll see a line under Display Adapters called something like “Intel Display Graphics”. Right click on this, and select Properties, then click the Details tab. In the drop-down box select Hardware IDs. Open Notepad, or a text editor of choice, and copy the four lines of the long Device IDs shown.

Let’s delete the driver that’s causing us issues by going to the Driver tab, clicking Uninstall, checking the box to delete the driver, and clicking OK. Decline the offer to restart because we’re not done.

Run gpedit.msc, and dig down into the following stack:

Computer Configuration > Administrative Templates > System > Device Installation > Device Installation Retrictions >  Prevent installation of devices that match any of these device IDs

Click “Enabled” then “Show” and here’s where you’d past the four lines copied from the Device Manager.

Click Apply, close the Group Policy Editor, and restart.

This should completely resolve any issues you’ve had on iMacs with Windows 8.1 or 10 that are having issues with downloaded Intel Graphics driver updates. You’re likely to see a failed update for the Intel Graphics driver in the future, but this is to be expected, and shouldn’t cause issues. In the event that a major system update breaks this, following these steps again should return your iMac to working order.

Most of these tips came courtesy of a long search day and this video, in Italian, which shows the process.

https://apple.stackexchange.com/questions/199553/windows-10-installation-using-boot-camp-crashes-in-imac-with-system-thread-exce