Can I create a system thread in a dispatch routine ?

Hi Everybody,
I have a problem . I need to create a system thread (of
normal priority)in a dispatch routine.
But immediately after this call it gives me an error in the application
saying accessing restricted memory and the program quits.
The thread has been started successfully ( which i can see through Windbg)
but i am not able to make any calls to dispatch routines once the thread
is created.

Does anyone know what the problem is??

Thank you in advance.

Vidya