Generating Security Token for SalesForce.com

If you want to use SalesForce SOAP API then you will need security token. If you dont have the security token SalesForce will generate Soap fault like this

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" 
xmlns:sf="urn:fault.enterprise.soap.sforce.com" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <soapenv:Body>
      <soapenv:Fault>
         <faultcode>sf:LOGIN_MUST_USE_SECURITY_TOKEN</faultcode>
         <faultstring>LOGIN_MUST_USE_SECURITY_TOKEN: Invalid username, password, security token; or user locked out. Are you at a new location? When accessing Salesforce--either via a desktop client or the API--from outside of your company’s trusted networks, you must add a security token to your password to log in. To receive a new security token, log in to salesforce.com at http://login.salesforce.com and click Setup | My Personal Information | Reset Security Token.</faultstring>
         <detail>
            <sf:LoginFault xsi:type="sf:LoginFault">
               <sf:exceptionCode>LOGIN_MUST_USE_SECURITY_TOKEN</sf:exceptionCode>
               <sf:exceptionMessage>Invalid username, password, security token; or user locked out. Are you at a new location? When accessing Salesforce--either via a desktop client or the API--from outside of your company’s trusted networks, you must add a security token to your password to log in. To receive a new security token, log in to salesforce.com at http://login.salesforce.com and click Setup | My Personal Information | Reset Security Token.</sf:exceptionMessage>
            </sf:LoginFault>
         </detail>
      </soapenv:Fault>
   </soapenv:Body>
</soapenv:Envelope>

Follow these steps to generate a security token

1. Login into your Salesforce account
2. Click on your use name and you will get drop down like this, click on My Settings sub menu
   
3. On the next page you will get submenu on the side click on Personal side menu, once its expanded click on Reset my security token link
   
4. Once your on the Reset My Security Token button and it will trigger security token generation process
   
5. In few minutes it will send email to your address with security token, use that for the subsequent SOAP calls