I just downloaded 2.4.7 and when I opened it up in my localhost, it wont start the installer.

The text that is showing is:
"Welcome to SilverStripe! This is the default homepage. You can edit this page by opening the CMS. You can now access the developer documentation, or begin the tutorials."\

I followed the install instructions on the website for wamp and can't work out why the installer isn't running.

Cheers,
Rob

This occurred when i copied the silverstripe folder, pasted it and renamed the copy

So this isn't a downloaded package from http://www.silverstripe.org/stable-download/ ?

if you copy/paste then it will keep things like the .htaccess file, this fiel will redirect your use of the "domain" to the existing domain from there and think it is installed.

Please always start with a downloaded package first, unless you know what you are doing with silverstripe.