Among other things, you must validate the ownership of your site with the search engines. Bing.com gives the following instructions:
Authenticate your website
Before you can use the Webmaster Center tools, you must demonstrate that you own the website by placing a Webmaster Center-provided authentication code at the root of your website. Webmaster Center uses authentication to ensure that only the rightful owners are provided with information about their websites.
A website is authenticated when, once you successfully log in to Webmaster Center, you click its link on the Site List webpage. If the authentication is successful, you are given access to the Webmaster Center tools for exploring the website.
There are two methods of authentication, both of which rely on Webmaster Center accessing the authentication code you’ve added to a registered website. The authentication code, which must be available to Webmaster Center at the root folder of your website’s registered host name space, can be added in two ways:
Upload an XML file to the root folder
Bing provides you with a custom XML file containing your authentication code that you can save to the root folder of your website. The name of the file is LiveSearchSiteAuth.xml.
The format of the authentication code content within the XML file should look similar to this example:
Add a <meta> tag to the default webpage
You can add a <meta> tag containing the authentication code to the <head> section of your default webpage. The format of the authentication code entry within the <head> section should look similar to this example:
<meta name=”msvalidate.01″ content=”0123456789ABCDEF0123456789ABCDEF” />
The authentication codes shown above are samples. The specific authentication code for your website can be found, once logged in to Webmaster Center, by browsing to the Site List.
Choosing which authentication method to use
Using the XML file. If you only have one Webmaster Center account for a website and you have easy access to the website’s root folder, using the XML file for authentication is a great choice. Just download the LiveSearchSiteAuth.xml file from the Authenticate ownership of your website webpage and save that file to the root folder of your website’s registered host name space. You can use the XML file method to simultaneously authenticate multiple user accounts by editing the XML file to include the unique authentication code for each additional account as a new <user> tag inside the <users> section of the XML file.
Using the <meta> tag. If you don’t have access to the root folder of your website, adding a <meta> tag in the <head> section of your default webpage might be a better option. To authenticate multiple user accounts, simply add an additional <meta> tag for each user account’s authentication code. Alternatively, you can have all members of your webmaster team use the same Webmaster Center tools logon account and just use one authentication code for your website.
When you add a website to Webmaster Center, you are automatically taken to the Authenticate Ownership of Website webpage. To go back later on to this webpage to access your authentication data again, log into Webmaster Center, browse to the Profile tool webpage, and then click Learn about the authentication process.
You can implement both authentication methods simultaneously if you want.
How authentication works
Webmaster Center provides authentication codes based on user accounts rather than the user’s individual web addresses. When you create a new authentication code, you can use that same new code for multiple websites (even updating the codes for previously registered websites if you want).
Webmaster Center auto-detects the authentication method used on your website. The XML file is the default method of authentication for Webmaster Center and is checked first with newly registered websites. However, once a website is authenticated, the last authentication method successfully used becomes the new default method for authenticating that website.
Because the XML file method is the initial default method for authentication, newly registered websites using the <meta> tag method might take a bit longer to authenticate on their first attempt.
The time-out duration for each method of authenticating a website is 14 seconds, after which an error is generated. If the first authentication method fails, the second method is automatically attempted. For information on resolving problems with authentication to Webmaster Center, see Authentication errors.
All websites registered with Webmaster Center before November 19, 2008, were issued authentication codes on a per-website basis. Each of those codes will continue to work going forward for their specific website. No change is required of your existing websites to continue using all of the Webmaster Center tools. However, all new Webmaster Center authentication codes created as of November 19, 2008, are issued on a per-account basis and can be repeatedly used to authenticate all of your registered websites, including previously registered websites. To get a new authentication code that works on a per-account basis, go to Add a site.
When you log in to Webmaster Center and click a website to use within your account, Webmaster Center uses a bot to authenticate your website. If the correct authentication code is found, then Webmaster Center stores a cookie on your computer that gives you access to the site for a 20-minute interval. If you exceed that time while logged in, Webmaster Center seamlessly re-authenticates your website and updates the cookie.
If your website redirects your default webpage to another location, the Webmaster Center authentication bot is usually able to follow that redirect and authenticate the website based on the information in the new webpage. Likewise, if you redirect your LiveSearchSiteAuth.xml file, Webmaster Center also follows that redirect as well. The user agent the Webmaster Center authentication bot uses is:
Common issues with authentication
Cloaking. This is when a website shows different content to a search engine web crawler than it shows a user with a web browser. If you have implemented cloaking on your website, it might be interfering with the Webmaster Center authentication bot’s ability to see the <meta> tags or LiveSearchSiteAuth.xml file on your website.
Redirects. If your website redirects your default webpage to multiple other webpages, then the Webmaster Center authentication bot might either stop following the redirects or time-out waiting for the final webpage to load.
Performance. If your web server is slow, if network congestion exists, or there are a great number of router hops between your web server and the Webmaster Center servers, the authentication bot can time-out waiting for the webpage to load.
Content Management Systems. Several content management systems block the user’s direct access to both the <head> tag within the HTML on their webpage and from adding files to the website’s root folder. In these cases, Webmaster Center is currently unable to authenticate the website, and subsequently these webmasters can’t log in.