Magento: Please enter a valid URL. Protocol is required (http://, https:// or ftp://) issue in Magento Installation

While installing Magento in the local server, in the configuration section, you may be asked to enter the base url. But the installation wizard will not accept the local server url. It is because Magento won’t consider the local server url as a valid url.
Solution:

For this you need to remove the validation for the particular section.

1. Open \app\design\install\default\default\template\install\config.phtml
2. Find the textbox where the base url is entered. It will be around line no 85 with name ‘config[unsecure_base_url]‘
3. Remove ‘validate-url’ from its class and save the file.

<li>
    <label for="base_url"><?php echo $this->__('Base URL') ?> <span class="required">*</span></label><br />
    <input type="text" name="config&#91;unsecure_base_url&#93;" id="base_url" value="<?php echo $this->getFormData()->getUnsecureBaseUrl() ?>" title="<?php echo Mage::helper('core')->quoteEscape($this->__('Base URL')) ?>" class="required-entry validate-url input-text" />
</li>

<li>
    <label for="base_url"><?php echo $this->__('Base URL') ?> <span class="required">*</span></label><br />
    <input type="text" name="config&#91;unsecure_base_url&#93;" id="base_url" value="<?php echo $this->getFormData()->getUnsecureBaseUrl() ?>" title="<?php echo Mage::helper('core')->quoteEscape($this->__('Base URL')) ?>" class="required-entry input-text" />
</li>

4.Now you can continue the installation.