Why is CoInitialize an undeclared identifier?

I use UniDac component to connect to PostgreSQL. My Query is running in a separate thread. Now when I use CoInitial开发者_如何学Goize in the thread, I receive this compiler error:

- [DCC Error] QryThread.pas(41): E2003 Undeclared identifier: 'CoInitialize'

Why?

---

Because ActiveX is missing in the uses list.