when i search for corby pc support on google.co.uk i get this result back

corby pc support services brigstock, cottingham, corby, desborough ...Corby PC Support provides a range of PC, networking, internet, hardware and sofrware support services for home users, small and medium business users.
corbypcsupport.co.uk/ - 17k - Cached - Similar pages

What I find really confusing is that the www. are missing ?
This has only happened in the last few days.
Can anyone help

The www and non www version point to the same point and google may index either.

Google has obviously decided that you wanted the non-www version of your site indexing.

If you only want one version of your site name to exist, you may canonicalize your domain name.

If you'd rather Google consider the www version of the site the default you can use 301 redirects to point the non www version to the www version. Or you can register for a free account with Google's Webmaster Tools and just select the option inside to use the www version of your site.

I wouldn't touch this, since it does not take effect to your website's page rankings. Keep both ways to access your website (with or without www) available to your visitors.

When you redirect BOTH WAYS ARE STILL THERE but it only ever shows ONE URI version.

AND it most certainly DOES affect your pages with the search engines.

just use 301 redirect. I use a 301 redirect on one of my site and both have the same valid PR which means google see's them as the same website.

I've done a sampling of many of the top websites on the internet, by entering www. as well as without a prefix, and EVERY major website I tested (Google, Yahoo, MSN, Amazon, Ebay, etc), canonicalizes their domain name into only one version, usually with the www., though I don't think one is better than the other.

I had the same thing with my website. All you need to do is register on Google Webmaster Tools and change it to have www. in front.

Unless of course you want any of the other search engines to honor your choice as well. Google Webmaster Central is a good option, but keep in mind it's only for Google.