windows - How does a virus load itself when you start your computer?

What i know is that most viruses use the registry/start up folder to add them to the start up list. Other may use an auto start windows service.

What about the rest, if the virus is not in the services or the start up list how does it start up then?

I recently had this problem i cleaned almost all suspicious start up registry entries and services and still the virus was starting up each time i booted into windows.

Any ideas?