Download the..... Windows installer clean up utility package.. Save it to your hard drive ( anywhere you wish as long as you know where to find it ). Once it's downloaded , install the programme by running the file. When that's done go to your desktop and click on start > all programs > then click on "Windows Install Cleanup". In the Windows Installer Clean Up Utility, remove all Windows Installer applications for the .NET Framework. Re-boot your PC and reinstall the Net Framework in the order i described in my last post.