.htaccess 301 redirect issue - apache

Question

I need 301 redirect from example.com to www.example.com. This is working solution, but when
I paste it in whole .htaccess site go down.
RewriteEngine On
RewriteCond %{HTTP_HOST} ^example.com
RewriteRule (.*) http://www.example.com/$1 [R=301,L]
Rest .htaccess file
php_flag magic_quotes_gpc off
php_flag magic_quotes_runtime off
php_flag register_globals off
RewriteEngine On
RewriteRule ^.htaccess$ - [F]
RewriteCond %{REQUEST_FILENAME} -f
RewriteRule ^(.*)$ $1 [L]
Options -Indexes
AddDefaultCharset windows-1251
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(service|news|search|project)/?$ index.php?menu=$1
RewriteRule ^error/([0-9]+)/?$ index.php?menu=error&loadinfo=$1
RewriteRule ^page/([0-9]+)/?$ index.php?menu=page&loadinfo=$1
RewriteRule ^news/([0-9]+)/?$ index.php?menu=news&loadinfo=$1
RewriteRule ^news/page-([0-9]+)/?$ index.php?menu=news&page=$1
RewriteRule ^service/([0-9]+)/?$ index.php?menu=service&category=$1
RewriteRule ^service/([0-9]+)/([0-9]+)/?$ index.php?menu=service&category=$1&loadinfo=$2
RewriteRule ^project/([0-9]+)/?$ index.php?menu=project&loadinfo=$1

Answer 1

Whats the AllowOverride value of the folder where you have your .htaccess? Your DocumentRoot (or VirtualHost) specification needs to be set to at least AllowOverride Options in order to allow php_flag within .htaccess files.
RewriteCond %{HTTP_HOST} ^example.com
RewriteRule (.*) http://www.example.com/$1 [R=301,L]