Can't locate install script

This may be a stupid question but I installed the piwik folder into my web space but I don’t know what URL to type in so I can get to the install script.

For instance, the path is www.mydomain.co.uk/piwik/ (I’ve swapped out my actual domain but you get the picture).

I’ve tried typing
www.mydomain.co.uk/piwik
www.mydomain.co.uk/piwik/
www.mydomain.co.uk/piwik/index.php
www.mydomain.co.uk/piwik/piwik.php

Nothing works. The browser just wants me to Save or Open the file as if it is to be downloaded.

I’m wondering whether I am making a naive error or whether there’s something lacking on my server. The server only had php version 5.2.17 so I uploaded an .htaccess file with the following code into the piwik folder:

AddHandler application/x-httpd-php55 .php .php5 .php4 .php3

Perhaps this is the problem.

Piwik requires PHP 5.3.2 or higher.
Maybe your .htaccess is not working correct.
You could try to upload a simple script and test if that works.