Noob question - software driver not as a service

Is it possible ? To install and load my software wdm driver without using the SCM?

No. ALL kernel mode drivers in Windows have to be registered as a service. The name used by your driver is its service name, not the driver’s file name.

It should be noted that there are two main different kinds of driver services. Plug 'n Play (PNP) and ‘legacy’ KM services. Legacy is very much a misnomer.

I am sure it was possible to link an export from another driver and have
that driver then load without being registered as a service.
I know it doesn’t help the OP, some driver still has to be a service in
this scenario, but not all the drivers.