Website displaying 'Default OaO frameset' as title [closed]

Question

I recently modified my .htaccess file on my website to:

ErrorDocument 404 http://www.example.co.uk/404.php

where example.co.uk is my replaced by the actual domain. Now, whenever I visit the website, it just comes up with that 404 page with the title 'Default OaO frameset'. My web.config file is as follows:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <defaultDocument enabled="true">
            <files>
                <clear />
                <add value="index.aspx" />
                <add value="index.asp" />
                <add value="index.htm" />
                <add value="index.html" />
                <add value="index.php" />
                <add value="home.aspx" />
                <add value="home.asp" />
                <add value="home.htm" />
                <add value="home.html" />
                <add value="home.php" />
                <add value="default.aspx" />
                <add value="default.asp" />
                <add value="default.htm" />
                <add value="default.html" />
                <add value="default.php" />
            </files>
        </defaultDocument>
        <security>
            <authentication>
                <basicAuthentication enabled="true" />
            </authentication>
        </security>
        <httpErrors errorMode="Custom">
            <remove statusCode="404" subStatusCode="-1" />
            <error statusCode="404" prefixLanguageFilePath="" path="/OaOInternal/DefaultWebs/sedoCurrent/Error404.aspx" responseMode="ExecuteURL" />
        </httpErrors>
    </system.webServer>
</configuration>

I'm being hosted by 1&1. So far I've tried deleting the .htaccess file, but it had no effect apart from making the main domain just display a blank screen with the title 'Default OaO frameset'.

Any help is really appreciated - I have no idea what to do.

Answer 1

I've fixed it now, so here's how I did it for anyone who needs it in the future:

I added this line:

DirectoryIndex index.php

to my .htaccess file in the root of my webspace. This way, it sets the index page to index.php, somehow overriding the web.config file and displaying index.php when as the default page for the domain name.