Check your website for malware

Check your website for malware using Google Safe Browsing Tool

http://www.google.com/safebrowsing/diagnostic?site=yourwebsite.com

Check a website in Google Cache

Use following URL

Replace mywebsite.com with the website url to check without http

http://webcache.googleusercontent.com/search?q=cache:mywebsite.com

Does position of keyword in URL affect ranking?

Redirect to www .htaccess

Create a .htaccess file with the below code, it will ensure that all requests coming in to domain.com will get redirected to www.domain.com
The .htaccess file needs to be placed in the root directory of your old website (i.e the same directory where your index file is placed)

Options +FollowSymlinks
RewriteEngine on
rewritecond %{http_host} ^domain.com [nc]
rewriterule ^(.*)$ http://www.domain.com/$1 [r=301,nc]

Please REPLACE domain.com and www.newdomain.com with your actual domain name.

Note* This .htaccess method of redirection works ONLY on Linux servers having the Apache Mod-Rewrite moduled enabled.

Reference: http://www.webconfs.com/how-to-redirect-a-webpage.php