You can find out who your domain name is registered to by doing a whois lookup.

Please visit: http://www.sitewizard.co.uk/whois.php

And type in your domain name into the 1st box

 Then click on the Find button depending on the domain type you will get different results please see below for a summary of each item.

Here is an example of a .co.uk whois lookup, you will find a description of each item in bold:

 Domain name: 
        sitewizard-support.co.uk 

This is the domain name that you have queried

Registrant:
        SiteWizard Technical Support

This identifies who the domain is registered to, this is normally your company name

Registrant type:
        Unknown 

This identifies the type of registration i.e if its registered to a LTD company, individual etc....

 Registrant's address: - 
        Ascot House
        22-24 Albion Place
        Maidstone
        Kent
        ME14 5DZ
        United Kingdom

This should be you companies address, if you need this changing please email support@sitewizard.co.uk

Registrar: - 
        Sitewizard Limited [Tag = ANET]
        URL: http://www.sitewizard.co.uk.

This identifies which ISP/Domain provider looks after the domain for you (ANET is Sitewizards Tag)

Relevant dates:  
        Registered on: 20-Mar-2009
        Renewal date:  20-Mar-2011

This identifies when the domain was registered and also when the domain is due for renewal

Registration status:
Registered until renewal date.

This identifies the status of the registration

Name servers:
ns1.hostingwizard.co.uk
ns2.hostingwizard.co.uk

This identifies which ISP has technical control of the domain, ie. who can change where the web/email goes to

Here is an example of a .com whois lookup, you will find a description of each item in bold:

Registration Service Provided By: Enom, Inc
Contact: CustomerSupport@enom.com
Visit: www.enom.com

Domain name:
 sitewizard-support.com

This is the domain name that you have queried

Registrant Contact:
   SiteWizard Ltd
   SiteWizard Technical Support ()
  
   Fax:
   Ascot House
   22-24 Albion Place
   Maidstone, Kent ME14 5DZ
   GB

This should be you companies address, if you need this changing please email support@sitewizard.co.uk

Administrative Contact:
   SiteWizard Ltd
   SiteWizard Technical Support (support@sitewizard.co.uk)
   +44.1622200045
   Fax: +44.1622206700
   Ascot House
   22-24 Albion Place
   Maidstone, Kent ME14 5DZ
   GB

This should be the address of your ISP the guys that are responsible of making admin changes to the domain 

Technical Contact:
   SiteWizard Ltd
   SiteWizard Technical Support (support@sitewizard.co.uk)
   +44.1622200045
   Fax: +44.1622206700
   Ascot House
   22-24 Albion Place
   Maidstone, Kent ME14 5DZ
   GB

This should be the address of your ISP the guys that are responsible of making technical changes to the domain  

Status:
Locked

This normally indicates the status of the transfer lock

Name Servers:
   ns1.hostingwizard.co.uk
   ns2.hostingwizard.co.uk

This identifies which ISP has technical control of the domain, ie. who can change where the web/email goes to

Creation date:
Expiration date: 26 Jun 2010 09:57:00

This identifies when the domain was registered and also when the domain is due for renewal