1.On the final page of the Lead-to-Account Conversion Wizard, click Finish.
2.The Lead will be converted to an Account, and you will return to the Opportunity record where you started the conversion process.
3.IMPORTANT: Save the Opportunity! You need to click Save before the Lead-to-Account conversion takes effect.
4.If you now open the related Lead record, you will see that it has been converted to an account; look in the Converted To Company/Contact area of the Lead edit form.
5.You can now proceed to Convert the Opportunity to an Event.