1: Complete novice.
2: I have downloaded MediaWiki 1.24, renamed the root file (ThamesBoats) and uploaded it to my host site. (www.windsorpropertylettings.co.uk) When I try to open MediaWiki in the browser I get the following message - MediaWiki 1.24 internal error MediaWiki 1.24 requires at least PHP version 5.3.2, you are using PHP 5.2.17. I have downloaded PHP 5.4.35 and now have the root file php-5.4.35 unpacked on my desktop. I can find no instruction in the MediaWiki installation document to tell me what to do with, or where to place the php-5.4.35 file. How do the two work together.
(I am already using php for a forum site - riverthamesforum.com, so 1: above is not strictly true!)