[SalesForce] Salesforce web to lead form issue

I am using salesforce-wordpress-to-lead plugin(version: 2.2.5) with wordpress(version: 3.8.1). I added organisation ID in settings and created a web to lead form. This form throws "Failed to connect to Salesforce.com." error, when i submit it. I did these process in local xampp server.

This is the HTML of the form generated by salesforce-wordpress-to-lead plugin

<form id="salesforce_w2l_lead_1" class="w2llead" method="post" action="#salesforce_w2l_lead_1">
<div class="sf_field sf_field_first_name sf_type_text"> <label class="w2llabel text" for="sf_first_name">First name: <sup><span class="required">*</span></sup></label>
    <input value="" id="sf_first_name" class="w2linput text" name="first_name" type="text">

</div><div class="sf_field sf_field_last_name sf_type_text">    <label class="w2llabel text" for="sf_last_name">Last name: <sup><span class="required">*</span></sup></label>
    <input value="" id="sf_last_name" class="w2linput text" name="last_name" type="text">

</div><div class="sf_field sf_field_email sf_type_text">    <label class="w2llabel text" for="sf_email">Email: <sup><span class="required">*</span></sup></label>
    <input value="" id="sf_email" class="w2linput text" name="email" type="text">

</div><div class="sf_field sf_field_phone sf_type_text">    <label class="w2llabel text" for="sf_phone">Phone:</label>
    <input value="" id="sf_phone" class="w2linput text" name="phone" type="text">

</div><div class="sf_field sf_field_description sf_type_textarea">  <label class="w2llabel textarea" for="sf_description">Message: <sup><span class="required">*</span></sup></label>
    <br>
    <textarea id="sf_description" class="w2linput textarea" name="description"></textarea>

</div>  
    <div class="sf_field sf_field_cb sf_type_checkbox"><label class="w2llabel checkbox w2llabel-checkbox-label"><input type="checkbox" name="w2lcc" class="w2linput checkbox" value="1"> Send me a copy</label></div>
    <input type="text" name="message" class="w2linput" value="" style="display: none;">
    <input type="hidden" name="form_id" class="w2linput" value="1">
    <div class="w2lsubmit"><input type="submit" name="w2lsubmit" class="w2linput submit" value="Submit">
</div></form>

when i print the post response in salesforce.php line no : 418, i got the below response.

WP_Error Object ( [errors] => Array ( [http_request_failed] => Array ( [0] => Failed connect to www.salesforce.com:443; No error ) ) [error_data] => Array ( ) ) Failed connect to www.salesforce.com:443; No error

Please help me to resolve this issue.