IIS Express Won't Run - Error (rc=800703f1) in UlInitialize

I suddenly can't debug anything in Visual Studio 2017 using IIS Express.

Symptoms

While debugging in VS2017, the output window shows the message below immediately.

The program '[13980] iisexpress.exe' has exited with code 0 (0x0).

Running IIS via Command Prompt: "C:\Program Files (x86)\IIS Express\iisexpress.exe" /port:50896 /path:"C:\Users\XXXXXXX\Documents\Visual Studio 2017\Projects\BT\ManageOIC\EnterpriseMedicalReportTool\\" /trace:error

Error (rc=800703f1) in UlInitialize. Exiting Error initializing ULATQ. hr = 800703f1

Copied template config file 'C:\Program Files (x86)\IIS Express\AppServer\applicationhost.config' to 'C:\Users\XXXXX~1\AppData\Local\Temp\iisexpress\applicationhost2018111183214194.config'
Updated configuration file 'C:\Users\XXXXX~1\AppData\Local\Temp\iisexpress\applicationhost2018111183214194.config' with given cmd line info.
Starting IIS Express ...
Initializing the W3 Server Started CTC = 3184968
W3 Server initializing WinSock.  CTC = 3184968
W3 Server WinSock initialized.  CTC = 3184968
W3 Server ThreadPool initialized (ipm has signalled).  CTC = 3184968
Start listenerChannel http:0
Error (rc=800703f1) in UlInitialize. Exiting
Error initializing ULATQ.  hr = 800703f1
Terminating W3_SERVER object
InitComplete event signalled
Process Model Shutdown called
Unable to start iisexpress.

The configuration registry database is corrupt.
For more information about the error, run iisexpress.exe with the tracing switch enabled**(/trace:error). 

In the event viewer, the following error is noted:

The worker process for app pool 'IISExpressAppPool', PID='4504', failed to initialize the http.sys communication when asked to start processing http requests and therefore will be considered ill by W3SVC and terminated.  The data field contains the error number.

Data field: 800703F1 - Err.exe suggests this may be a registry problem.

What I've Tried

• Changing the port for IIS Express to several different open ports
• Deleting the .vs folder in Visual Studio.
• Running a different project.
• Creating a new MVC web app and running it.
• Reinstalling IIS Express via Microsoft Website. (And restarting after.)
• Reinstalling IIS Express via Visual Studio Installer. (And restarting after.)
• Repairing Visual Studio. (And restarting after.)
• Manually running IIS from command line via command above on IIS 10.
• Uninstalling IIS 10 and installing IIS 8
• Manually running IIS from command line via command above on IIS 8.
• Running sfc /scannow (No issues found)
• Checked for recent Windows updates (none shown)
• Updated visual studio