How to rename an IIS Express website in Visual Studio 2012

I initially created a site in Webmatrix 2. I just called it website1. I’ve now been working on the site in Visual Studio 2012 and I would like to rename it. It doesn’t appear you can rename it directly, but in the .sln file there is a project entry which contains the string “website1”. I renamed it and re-started VS. The new name briefly displays but then gets overwritten with the original name. So now I have the .sln file with the new name and nowhere within the folders does it reference the old name – i’ve searched every file. But yet VS insists on calling the site website1. So i’m totally confused.