By default all new web sites are configured on our servers with ASP.NET 3.5 SP1 (compatible with ASP.NET 2.0)
To change this version:
1. Login to our web site
2. Go to the Web Applications section.
3. Click the Edit link to the right hand side of the page.
4. There you can choose ASP.NET 4.0 from the dropdown box.
5. Click the Edit button to save the changes.