WinNT debugger - int 2

Does anyone know how to set the single step flag (int 2) for a
process?

I’m writing a debugger and would like to get the process being
debugged into single step mode. Using Get/SetThreadContext
does not seem to work - I can set most of the other flags but if I set
the int 2 bit and call SetThreadContext the bit is ignored.

Any ideas?

Thanks