If you tried to deploy your asp.net application on Win 08 – IIS7 and you were getting this error:
Unrecognized attribute ‘targetFramework’ 4.0
This means the application pool that runs your website is not configured to run under .NET Framework 4.0.
On IIS 7:
1) Click on your application pool.
2) Click on the right pane, Advanced settings.
3) Under General Tab, Select .NET Framework Version.
4) Select v 4.0.
5) Recycle your application pool by right click on it.
6) Refresh your page.
Refresh your page and it works
Hope this helps…