PostgreSQL Error : server closed the connection unexpectedly

Question

I cannot connect to PostgreSQL server from PgAdmin III , so i get this error:

Error connecting to the server: server closed the connection unexpectedly

This probably means the server terminated abnormally before or while processing the request.

i have got this error 2 days ago but after restarting the computer the problem disappears , but this time i have restarted it too many times vainly.

i'm using PostgreSQL 9.0.5 on windows 7 with ArcSDE 10.1 (Arcgis Spatial Database add-on), i have deactivated the antivirus and firewall.

I have tried to reinstall PgSQL but the problem persists.

How i can connect to my Pgsql service and get ride from this error ?