I am using Windows Vista service pack 1
This was the error log
[07/04/14,19:49:29] Microsoft .NET Framework 3.0SP1 (CBS): [2] Error: Installation failed for component Microsoft .NET Framework 3.0SP1 (CBS). MSI returned error code -2146762496[07/04/14,19:51:38] WapUI: [2] DepCheck indicates Microsoft .NET Framework 3.0SP1 (CBS) is not installed.
[07/04/14,20:10:41] Microsoft .NET Framework 3.0SP1 (CBS): [2] Error: Installation failed for component Microsoft .NET Framework 3.0SP1 (CBS). MSI returned error code -2146762496
[07/04/14,20:14:35] WapUI: [2] DepCheck indicates Microsoft .NET Framework 3.0SP1 (CBS) is not installed.
[07/04/14,21:32:49] Microsoft .NET Framework 3.0SP1 (CBS): [2] Error: Installation failed for component Microsoft .NET Framework 3.0SP1 (CBS). MSI returned error code -2146762496
[07/04/14,21:35:45] WapUI: [2] DepCheck indicates Microsoft .NET Framework 3.0SP1 (CBS) is not installed.