codeigniter working fine on local but not on web server. 404 Error

I contacted my host. They said that there was a problem in php handler.

Apart from this IIS doesn't read .htaccess file, Instead I make a file web.config and replace with .htaccess in mysite/httpdocs/demo/test/site/

Content of web.config file is

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

<system.webServer>

    <httpErrors errorMode="Detailed" />
    <asp scriptErrorSentToBrowser="true"/>

    <rewrite>
    <rules>
        <rule name="RuleRemoveIndex" stopProcessing="true">
            <match url="^(.*)$" ignoreCase="false" />
            <conditions>
                <add input="{REQUEST_FILENAME}" matchType="IsFile" ignoreCase="false" negate="true" />
                <add input="{REQUEST_FILENAME}" matchType="IsDirectory" ignoreCase="false" negate="true" />
            </conditions>
            <action type="Rewrite" url="index.php/{R:1}" appendQueryString="true"/>
        </rule>
    </rules>
    </rewrite>

</system.webServer>

<system.web>
    <customErrors mode="Off"/>
    <compilation debug="true"/>
</system.web>

</configuration>

Now the website is up and running. Thanks for the support.