Yes, you can use ASP.Net 1.1, ASP.Net 2, PHP 4 & PHP 5 simultaneously. They are installed on all Windows servers. So if you have windows hosting account with us, you can now experiment with those 4 versions at the same time

In order to use them, you must first select the version you want in your hosting control panel.

1. Login to control panel and choose Web Options.
2. If you have more than 1 domain then choose which domain you want.
3. Change the version
   

That’s it. You can start playing with all 4 versions, which ever you want

By default, HSphere does not include index.php as directory index or main file on Windows Hosting. That means, if you want to use index.php as your main file, you will need to modify your directory index setting in you hosting control panel and put index.php as your directory index.

Read below article for detail info:

Directory Indexes

This tool allows you to set your own index pages instead of those specified in the default settings. In other words, you can tell your visitors’ browsers which page to load as they hit your domain. Usually, it’s /index.html by default, but you can set any other custom welcome page.

Example: If a visitor goes to your site http://www.example.com, the first page to open will be http://www.example.com/index.html. However, if you set /welcome.html as the directory index, the page to open will be http://www.example.com/welcome.html.

Warning: your custom index pages won’t add to the defaults; they will replace them. Therefore, make sure to enter the full list of indexes you would like to have in your configuration.

To set your custom directory indexes, do the following:

1. Select Quick Access in the Account menu.
2. Click the Web Options icon on the page that shows.
3. Click the Edit icon next to the domain you need.
4. On the Web Service page, scroll down to find the Directory Indexes option and turn it on.
5. Agree with the charges.
6. In the box that appears, enter the names for files that will be treated as indexes. Put file names in the descending order of priority and separate them with spaces (e.g. index.html cgi.bin about.html).
   
7. Skip this step if you are using a Windows-based plan. At the top of the Web Service page, click the Apply link for the Server configuration to change. The changes will take effect within 15 minutes.
8. To edit the list you have made, click the Edit icon next to the Directory Indexes option: with spaces (e.g. index.html cgi.bin about.html).
   
   If you are using a Unix-based plan, click the Apply link at the top of the Web Service page.