could not find JavaScript runtime error while doing rails -s

Hello

Iam a new bie in rails and facing problem while running rails server

Iam not able to install my rails properly
Error: Could not find Javascript runtime error

I tried to resolve it by changing the gemfile in my project by uncommenting therubyracer in it ,but still the problem is not solved

Please help.

Thanks and Regards

Etika

Install nodejs.