You can create a new DS-160 Application and book appointmnet using that.
Check these answers :
http://redbus2us.com/qa/63/regarding-multiple-ds-160-submission
http://redbus2us.com/qa/6868/can-we-fill-multiple-ds-160-forms
Also, you may read this experience shared by user :
http://redbus2us.com/how-to-fill-ds-160-for-missing-surname-family-name-in-passport-for-us-visa-experience/
You can talk to the US Visa Call center folks, if you have any doubts http://www.ustraveldocs.com/in/in-main-contactus.asp#contactinfo