postgres stops on win 2003

GletscherHi everybody,

I used the instalation routine "postgresql-8.0.msi" to install the "PostgreSQL 8.0.0 on i686-pc-mingw32" 
service on a Windows 2003 standard PC. 
After instalation is complete, i changed the shared memory in the postgresql.conf file
and tried to restart the server, but i received the message, that the server was 
successfully started and stoppd, because it was in idle. I have reinstalled Postgres, but
every time i get the same message when i try to restart it. 
Does anybody know what is wrong?

Thanx in advance

Borislav Roussanov