Umbraco - web.config issue when installing

I'm trying to install a default Umbraco installation on IIS7, and I开发者_Python百科'm getting the following error on my (unmodified) web.config file, any ideas?

Config Error The configuration section 'system.web.extensions' cannot be read because it is missing a section declaration

Thanks,

I'm going to assume you are using the current version of Umbraco 4.5.2 as offered on the Codeplex site...

By default, Umbraco is configured to use .Net 2.0 (not .Net 4.0). Go to your IIS Management Console, select ApplicationPools and double-click your website. Make sure the .Net Framework is set to 2.0.

Also make sure the server you are running the IIS on has .Net 2.0 installed!

If you can provide more information from the server's error page, I can help better pinpoint the error...