https://bugs.launchpad.net/ubuntu/+source/kdebase/+bug/505754
Until the developers fix this, I thought of educating others as to how to get it working, hence the blog. Go to system settings, click the advanced tab and then you will find the desktop search feature there. Please see the below image.

Go in to desktop search and enable Nepomuk Semantic Desktop and Strigi Desktop File Indexer.
