After 2 days of testing I'm able to run nginx on Windows Vista x64 SP2 with PHP
I'm using a Kevin Worthington 1.04 cygwin build with 2 worker processes and 5 child's of php-cgi.exe
On a hardware like Laptop with Intel Core2Duo P8400 2.26GHz with 3GB of RAM and 250GB 7200 1/min HDD
I've been able to receive results like below:

nginx + PHP
[Tested locally with Apache Benche - using: ab.exe -n 5000 -c 1000 127.0.0.1/
The file reached is index.php with code only <?php phpinfo(); ?>]

nginx + php 5.3.6 x86 build thread-safe -> 199 requests / sec
nginx + php 5.3.6 x86 build NON thread-safe -> 208 requests / sec
nginx + php 5.3.6 x64 build thread-safe -> 176 requests / sec
nginx + php 5.3.6 x64 build NON thread-safe -> 185 requests / sec

nginx + HTML
[Tested locally with Apache Benche - using: ab.exe -n 5000 -c 1000 127.0.0.1/
The file reached is index.html created by Kevin Worthington]

nginx with multi_accept off -> 445 requests / sec
nginx with multi_accept on -> 900 requests / sec

Level of failed requests never was higher than 5 requests.

My nginx.conf
#user nobody;
worker_processes 2;

#error_log logs/error.log debug;
#error_log logs/error.log notice;
#error_log logs/error.log error;

pid logs/nginx.pid;


events {
worker_connections 2048;

# multi_accept gives wings but only with HTML - not PHP!!!
multi_accept off;
accept_mutex on;
}


http {
include mime.types;
default_type application/octet-stream;

#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';

access_log off;
#access_log logs/access.log main;

sendfile on;
#tcp_nopush on;

# Enable only on CYGWIN nginx build !!
ssl_session_cache shared:SSL:10m;
ssl_session_timeout 5m;

keepalive_timeout 30;

gzip on;
gzip_min_length 1000;
gzip_proxied expired no-cache no-store private auth;
gzip_types text/plain application/xml;
gzip_disable "MSIE [1-6]\.";

# Settings for multiple php-cgi.exe
#
upstream backend {
server 127.0.0.1:9000;
server 127.0.0.1:9001;
server 127.0.0.1:9002;
server 127.0.0.1:9003;
server 127.0.0.1:9004;
}

server {
listen 80;
listen 443 ssl;
server_name www.sklep.beta.ostrowwlkp.pl;
ssl_certificate server.crt;
ssl_certificate_key server.key;

#charset koi8-r;

#access_log logs/host.access.log main;

location / {
root html;
index index.php;
}

# Statyczne elementy mogą być cache'owane przez przeglądarkę przez określoną ilość dni [lub max]
#
#location ~* \.(ico|css|js|gif|jpe?g|png)$ {
# expires 30d;
#}

#error_page 404 /404.html;

# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}

# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
location ~ \.php$ {
root html;
fastcgi_pass backend;
#fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME c:/nginx/html/$fastcgi_script_name;
include fastcgi_params;
}

# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}
}



Any proposition for improvement ???
Enabling multi_accept on; with PHP pages is crashing connection.