We have had several reports of Windows 7 systems that will no longer boot after installing Microsoft 2019-08 Security Update KB4512506.
Since initially being released on Tuesday 8/13/2019, Microsoft has updated the patch to avoid installing on systems where it would cause this issue. If you have already installed the 2019-08 Update, the Windows 7 exacqVision server will no longer boot and you will see the screen below.
This also affects Windows Server 2008 but we have not had any reports regarding this OS. New version of Windows are not affected.

Recovery options by motherboard type

We recommend this recovery method for all non Q87 Motherboards.
You should use this method for Q87 motherboard systems that do not have onboard recovery option.
If onboard recovery is available and you also have a configuration backup, It is our recommendation to use the onboard recovery option.
Onboard Recovery instructions are at the end of this page

Pre-Site Visit Preparation

Download WES7 disc and Rufus USB tool
Username/Password = guest/exacqvisionip

Prepare USB drive

Double-Click on the Rufus utility to run
Choose settings pictured below in screenshot

Boot to USB drive and apply the fix

Plug the USB thumb drive into an available USB port
Turn on the exacqVision server
Choose F8 (Q87 Motherboard) or F10 (DQ77 Motherboard) while the system is booting
Choose the thumb drive (typically the thumb manufacturer name) from the boot menu
NOTE: DQ77 Motherboard Boot menu (F10) will not show the manufacturers name for the USB device. It will show "USB number HDD" (USB 1 HDD) (the number may incrementally change). It might also be named: USB Generic Storage.

Choose "Launch WinPE Command Prompt (Press "L" key on Keyboard)
NOTE: If you don't have mouse control, reboot and try again or use keyboard to control.

Type: "dism.exe /image:C:\ /cleanup-image /revertpendingactions" and choose Enter on the keyboard
It will state "Reverting pending actions from the image..."
Then "The operation completed successfully"

NOTE: If you receive the message below, you can ignore.

After you reboot the system, you will see a Windows boot messages stating "Preparing to configure Windows. Do not turn off your computer" and "Failure configuring Windows Updates, Reverting changes. Do not turn off your computer".

NOTE: After you are able to boot to your Windows installation; Please turn off Windows updates or hide KB4512506. There is a chance the old Windows update is cached and could reinstall. We are investigating a method of clearing the already downloaded update from cache.

Navigate to Control panel ==> Windows update (you may need to choose "Check for Updates" again to show the available update).
Click on the available update as shown below

Right click on the update (KB4512506) and choose "Hide Update"

Onboard Recovery Option
Recovery Instructions

ExacqVision EL, A, S and Z series servers built after 10/17/2015 included a special partition to allow for quick and easy system restoration to factory default conditions. This recovery will only affect your operating system drive. The exacqVision serial number will identify the year and month the system was build.
(ex. ER1542xxxxxx was built the 42nd week of 2015)

NOTE: After the recovery, you will need to import your configuration backup to restore your configuration and camera association with pre-existing video data.

As the exacqVision server is booting, press the "R" (for some older systems it might be "S") to initiate the onboard recovery.

Select "Exacq Factory Restore" to begin recovery.

You will be prompted to confirm:

Press the "y" key on the keyboard once and the system recovery will complete itself. The entire process often only takes a few minutes but depends on the system.

If you need assistance, please contact Exacq Support at 317-845-5710 Monday - Friday 8am to 8pm EST