[mod-rewrite] How do you enable mod_rewrite on any OS?

In my case, issue was occured even after all these configurations have done (@Pekka has mentioned changes in httpd.conf & .htaccess files). It was resolved only after I add

<Directory "project/path">
  Order allow,deny
  Allow from all
  AllowOverride All
</Directory>

to virtual host configuration in vhost file

Edit on 29/09/2017 (For Apache 2.4 <) Refer this answer

<VirtualHost dropbox.local:80>
DocumentRoot "E:/Documenten/Dropbox/Dropbox/dummy-htdocs"
ServerName dropbox.local
ErrorLog "logs/dropbox.local-error.log"
CustomLog "logs/dropbox.local-access.log" combined
<Directory "E:/Documenten/Dropbox/Dropbox/dummy-htdocs">
    # AllowOverride All      # Deprecated
    # Order Allow,Deny       # Deprecated
    # Allow from all         # Deprecated

    # --New way of doing it
    Require all granted    
</Directory>