There are two different cases of an error with the code 0xc00000e9, it can appear when installing Windows Vista, Windows 7 and Windows 8, or in an already installed and long-running system.

The official Microsoft website indicates that the ACTIVE_EX_WORKER_THREAD_TERMINATION blue screen of death with a digital stop code of 0x000000E9 appears on Windows 7 and other builds of operating systems due to a driver failure or a mismatch between the version and bit depth of Windows. Sometimes the file that causes the BSOD is displayed on the screen. However, in some cases, to determine it, you need to enable a small memory dump and analyze the file using the BlueScreenView program.

As for foreign forums and sites, their users note that the error 0x000000E9 appears when the registry is damaged, when there is a lack of some kind of update package, when the processor overheats or when RAM errors occur.

Since it is impossible to name the exact culprit of the error 0x000000E9 ACTIVE_EX_WORKER_THREAD_TERMINATION, then to fix the blue screen of death, you will need to conduct a complete diagnosis of the installed equipment and check the system.

First of all, if ACTIVE_EX_WORKER_THREAD_TERMINATION blue screen of death appears on your PC, then you need to check the status of the frameworks (Microsoft .NetFramework). What version of this component is installed? Does it match the version of Windows itself.

Recall which versions of the framework are needed and for which versions of Windows.

It is important that one version of .NetFramework is installed on the PC. When updating the operating system, it will receive its update, which will be loaded specifically for the version and capacity of the system.

If the frameworks are installed correctly, then the solution to the error must continue with updating or reinstalling the drivers. First you need to open the Device Manager (Win + R, devmgmt.msc), expand the entire tree menu. If there is an indication of a failed driver near some element, then you need to delete it (if it is not deleted, then uninstall via Safe Mode). Next, you need to download a driver from the official site of the hardware manufacturer that matches the version and bit depth of Windows. Run its installation.

In case you don’t know which driver is failing, we recommend downloading any program to automatically search for and update drivers. Some motherboard manufacturers have special utilities for finding software, Windows 10 itself can load drivers, or you can download DriverPack Solution or DriverHub.

If the driver update did not bring a positive result and the BSOD still crashes, it is worth updating the entire operating system. To do this, open the "Control Panel", "System and Security", "Windows Update" and install all the important updates.

After that you need to check all installed programs. Perhaps some software is incompatible with Windows or antivirus. Therefore, we recommend temporarily disabling the antivirus and testing the PC. Next, look in the "Programs and Features" which game or program was last installed or received updates.

You need to remove software that conflicts with the defender or add the program to antivirus exceptions.

If everything is in order with the programs, you have reinstalled the driver, then the problem may be caused by a hardware failure. In this case, we recommend:

Using the program Victoria HDD, MHDD, HDDScan or any other program for diagnosing a hard disk, check your drive. Using the MemTest86 program, you need to test the RAM for errors. Using the AIDA64 tool, we recommend checking the processor’s temperature and voltage. Perhaps the processor is overheating or there is not enough power to the elements. We load the video card with the FurMark program. If everything is in order with the installed components, and the error after the diagnosis is not resolved, we recommend that you restore Windows 7 using the installation disk or reinstall the operating system altogether.

4 Recommendations for the Elimination of BSoD:

1. 0x000000E9: ACTIVE_EX_WORKER_THREAD_TERMINATION may appear due to errors in the code of the operating system itself. Microsoft is constantly working to correct such errors, releasing patches and service packs. Installed the latest update package (Service pack) and the constant updating of the system will save a lot of errors.
2. If 0x000000E9: ACTIVE_EX_WORKER_THREAD_TERMINATION appeared after the newly installed device driver or program. It is necessary to roll back the driver to an earlier version. With programs, things are easier, removing them will eliminate the cause of the failure. The “Run Last Known Good Configuration” option may be useful.
3. If 0x000000E9: ACTIVE_EX_WORKER_THREAD_TERMINATION began to appear after you have connected a new device to the system, then you need to check it for compatibility with your operating system. If the device is compatible, then you need to download the latest drivers from the official website of the manufacturer and install them. If the latest drivers are installed, you need to install an earlier version of the drivers. If the device is incompatible with the operating system, then it is necessary either to change this device or to change the operating system that supports this device.
4. Very often the cause of the appearance of 0x000000E9: ACTIVE_EX_WORKER_THREAD_TERMINATION is a malfunction of the RAM. To test it, you can use testing programs, such as memtest86+.