My Web site is very slow create a htaccess file and put inside it:

# Turn on Expires and set default to 0
ExpiresActive On
ExpiresDefault A0

# Set up caching on media files for 1 year (forever?)
<FilesMatch "\.(ico|flv|pdf|mov|mp3|wmv|ppt)$">
  ExpiresDefault A29030400
  Header append Cache-Control "public"
</FilesMatch>


# Set up caching on media files for 1 month
<FilesMatch "\.(gif|jpg|jpeg|png|swf|js|css)$">
  ExpiresDefault A2419200
  Header append Cache-Control "public, proxy-revalidate"
</FilesMatch>


# Set up caching on media files for 1 week
<FilesMatch "\.(xml|txt|html)$">
  ExpiresDefault A604800
  Header append Cache-Control "public, proxy-revalidate"
</FilesMatch>

# Force no caching for dynamic files
<FilesMatch "\.(php|cgi|pl|htm)$">
  ExpiresDefault A0

  Header set Cache-Control "no-cache, no-store, must-revalidate, max-age=0, proxy-revalidate, no-transform"
  Header set Pragma "no-cache"
</FilesMatch>