1.indexed in yahoo but only show without www Even it does not show when i type site:www.mydomain.com 2. Recently i made minor changes in my site. I edited the header tag, Now my site is not coming in ranking. I am not SEO professional. What may be the probable reason. Thanks
You can get this fix by do 301 redirect from non www version to www version. These tutorials could do the tricks How to 301 Redirect Non-WWW to WWW URLs 301 redirect from non-www to www I assume your header changed has included title tag. Every change made on title tag, even a single character added / removed / modified will effect your website ranking significantly. It would take times around 2-6 weeks before come stable again. However, this is not a guaranteed of better ranking anyway. Your come back ranking can be - better / no changed / worse, depends on how proper change you made.
I personally prefer using .htaccess to redirect. It's really simple and more effective. Also, I know you're talking about Yahoo, but in Google Webmaster, make sure to set your preference in the settings to use the www instead of no preference (which is the default).
Thanks, i just do 301 direct, hope this way will work for my site to back yahoo indexed with www.mydomain.com