How can i enable task manager to a slave drive

A friend of mine brought me a computer that boots up, but automatically fills screen with a fake Microsoft anti-virus and asks you to pay money. The task manager is now disabled and no shortcut keys work. I’m not seing the desktop, start menu or anything.

So I slaved it to my main PC and performed spyware clean, but now all I see is their backgroud when I turn on the PC. No icons and the task manager is still disabled.

I’m sure I could manage by having the task manager enabled, but I’m not sure how to do it when it’s plugged in as a slave drive to my main PC.

Does anyone know?