OK, so I'm now able to uninstall stuff properly, that link turned out to actually work. The iTunes still doesn't work though. Which is now an even bigger problem because I uninstalled the iTunes I already have.
There have been some updates which I need to get round to doing I suppose I might as well try them.
By the way, these are forums and help sites I've already looked at:
http://www.google.co.uk/url?sa=t&sou...RhPIjRGy4JDLmw
http://www.google.co.uk/url?sa=t&sou...JT9HTAWpciNlyg
http://www.google.co.uk/url?sa=t&sou...pRAVhUSY3RdlTA
And in case anyone's wondering, I'm using Vista, HP Pavilion, 2GB RAM, 32-bit, 1.73 GHz processor. Not that any of that really matters, apart from the Vista thing :V