Nignx boot error: ngx_master_520 the event was not signaled for 5s

I'm trying to set up an SSL certificate on my web server that uses Windows 2008 RC2 and Nginx. I always encounter an error in the log file and this causes Nginx not to run. The error is:

  

Error in initializing Nignx: ngx_master_520 the event was not signaled for 5s

The file nginx.conf is set up as below:

server {
   listen 443; 
   ssl on; 
   ssl_certificate c: /nginx/ssl/SSL.pem; 
   ssl_certificate_key c: /nginx/ssl/privatekey.key; 

   server_name localhost; 
   location / {
     root html; 
     index index.html; 
  } 
}