Domain name change with minimum seo impact

I am owner of an existing (3 yr. old) domain http://www.22shrutiharmonium.com and my website appears at the top of the search results in case of some search phrases like "22 shruti" , "22 shruti harmonium", "shruti harmonium" etc., in major search engines like google, bing, yahoo etc. My website has also been listed in Wikipedia (http://en.wikipedia.org/wiki/Harmonium).

Now, I wish to provide more generalized information on my site and hence I want to change the domain name to www dot 22shruti dot com.

Please guide me, about the ways / steps to retain the search engine credentials of my website OR, if not, then minimize the decrease in ranks, if I change the domain name.

Note : My website has windows web hosting.

You will want to setup the new domain's hosting and point the old domain as an alias domain. From there, in your Apache config or .htaccess access file, you want to use Apache's mod_rewrite to complete a 301 redirect on your old domain and any sub-pages to point to the new domains.

When you do a 301 redirect, most common search engines will transfer the SEO for that page/link/domain to the new domain over time - usually 3-6 months if not sooner.

Here is an example .htaccess file:

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^(www.)?old-domain.com
RewriteRule ^(.*) http://new-domain.com/$1 [R=301,L]

Keep the old domain for a while (however long you want, maybe until it expires from the registrar?) and use a HTTP 301 Redirect to send users to the new domain.

Search engines usually behave sanely with 301 redirects & will aggregate the old & new domain info...