Try to uninstall the .NET version you have, run the
cleanup tool and reinstall. To manually remove and reinstall the .NET
Framework, follow these steps:
1. Remove the .NET Framework.
1. Click Start , and then click
Control Panel .
2. Double-click Add or Remove Programs .
3. Note each version
of the .NET Framework that is already installed on the computer. Then,
uninstall all the versions of the .NET Framework.
4. When you are prompted, restart the computer.
2. Use the Windows Installer CleanUp Utility to clean up the MSI database state for all the versions of the .NET Framework.