Windows 7 x64 driver ERROR_INVALID_IMAGE_HASH

Question

I have recently been trying to create my first driver using WDK with Visual Studio 2015 and so far I was able to generate a .sys file, along with the .cert and the other files generated by default.

My problem comes when I try to dynamically load the driver, the function fails with the code 577, ERROR_INVALID_IMAGE_HASH.

Here is the code I am using to load the driver:

#include <windows.h>
#include <stdio.h>

int _cdecl main(void)
{
   HANDLE hSCManager;
   HANDLE hService;
   SERVICE_STATUS ss;
   DWORD error;
   PHANDLE hToken;

   hSCManager = OpenSCManager(NULL, NULL, SC_MANAGER_CREATE_SERVICE);
   error = GetLastError();
   printf("Load Driver\n");

   if (hSCManager)
   {
       printf("Create Service\n");

       hService = CreateService(hSCManager
        , "test"
        , "test Driver"
        , SERVICE_START | DELETE | SERVICE_STOP
        , SERVICE_KERNEL_DRIVER
        , SERVICE_DEMAND_START
        , SERVICE_ERROR_IGNORE
        , "C:\\driver_test.sys"
        , NULL, NULL, NULL, NULL, NULL);
       error = GetLastError();
       if(error == ERROR_SERVICE_EXISTS)
       {
           error = 0;
       }
       if(!hService)
       {
           hService = OpenService(hSCManager, "test", SERVICE_START | DELETE
           | SERVICE_STOP);
       }
       error = GetLastError();
       if (hService)
       {
           printf("Start Service\n");
           StartService(hService, 0, NULL);
           error = GetLastError();
           if (error!= NO_ERROR)
           {
               printf("Error: %d\nPress Enter to exit", error);
               getchar();
           }
           else
           {
               printf("SUCCESS\nPress Enter to close service\n");
               getchar();

           }

           ControlService(hService, SERVICE_CONTROL_STOP, &ss);
           CloseServiceHandle(hService);

           DeleteService(hService);
       }

       CloseServiceHandle(hSCManager);
   }

   return 0;
}

The error shows up once I call GetLastError function right after StartService function is called.

So far, what I have understood is that the driver I am trying to test doesn't have a valid certificate, or at least windows is not aware of its existence.

I have therefore tried using signtool in the developper command prompt for vs2015 and I was able to succesfully sign my driver.

Unfortunately, I went back to trying to load it and I still got the same error.

What would be the best course of action to fix this?

Thanks