Nofollow is an HTML attribute that instruct search engines not to crawl the link to which it is attached. Comment author URL in WordPress, Blogger and all other CMS are nofollowed by default. This prevents spammers from gaining search engine advantage by just commenting on any of these blogs. I personally use a Firefox addon called nodofollow to differentiate from dofollow and nofollow. The addon will highlight nofollow links with a light red color. Recently after installing WordPress in downhub.com, I found that all external links on the blog are nofollow. So that means none of my blogs posts will be crawled by Google and other search engines. This happens sometimes when we install WordPress. Inexperienced users who don’t know about nofollow will left them unfixed, leading to long term search engine traffic lose. So here is how you can Fix all links nofollow issue after WordPress installation.
I assume that the target blog is using WordPress 2.8 or any other latest version. Now from dashboard open privacy and select the first option ” I would like my blog to be visible to everyone, including search engines (like Google, Sphere, Technorati) and archivers “. So that fixes nofollow issue from WordPress external links after installation. This seems very simple .But when u search in Google and WordPress support forums, you would see many people who asking doubts on this.