Postgres service stops when I kill client backend on Windows

I’ve started PostgreSQL server on Windows and then I kill client
backend’s process by taskkill the service was stopped: 

postgres=# select pg_backend_pid();
 pg_backend_pid
----------------
           1976

postgres=# \! taskkill /pid 1976 /f
SUCCESS: The process with PID 1976 has been terminated.
postgres=# select 1;
server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!>

If I kill backend’s process on Linux then service not failing. So
what’s the problem? Why PostgreSQL is so strange on Windows?

------
Dmitry Vasilyev
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company