.Net Framework 3.5 not being installed on Windows Server 2008

Server : Windows Server 2008 (Standard) Service pack 2

All website running before on Framework 3.5 was stopped working and was giving error :

Error Code : 0x80070032
Config Error : The configuration section 'appSettings' cannot be read because it is missing a section declaration

So I tried to repair & re-install framework 3.5 but it was giving error while repairing or re-installing. Even it was not allow to uninstall it. So uninstalled it by using Clean-up utility given on this link -http://blogs.msdn.com/b/astebner/archive/2008/08/28/8904493.aspx Now there is no framework 3.5 on server but it is not allowing to install it. Just gives message "Setup Error", no more detail and leaves success message in Event Viewer

Product: Microsoft .NET Framework 3.5 SP1 -- Installation completed successfully.

Other message in event viewer is

Windows Installer installed the product. Product Name: Microsoft .NET Framework 3.5 SP1. Product Version: 3.5.30729. Product Language: 0. Installation success or error status: 0.

Is there any solution to install it?

Log file :

2) MSIad0cb.LOG