CreateWindowEx vs CreateThread

[Grincheux]

I create a thread with CreateThread.
In this thread I call GetCurrentThread to get an instance handle
In CreateWindowEx I replace the HINSTANCE parameter with the GetCurrentThread handle.

The window is not created.
How can I do ?

Thanks

[asmfan]

HINSTANCE == HMODULE == Base address of process loading (basically 400000h for exe)
Process can have many threads (hThread) but only one HINSTANCE.