I found a solution.
1.Download a special uninstalling software(I recommend Total Uninstall Pro)
2.Install and open the software.
3.Find and uninstall every .NET program you see(they might be not shown in Total Uninstall Pro untill you select "Show system components" at the bottom of the screen to YES) its important to delete the .NET programs from the registry too.So don't use just the build in uninstaller of the programs!!!
4.Restart your computer
5.Open Windows Update and download every .NET update you see.
6.After downloading finish click "Restart now" option of Windows Update window.
P.S I hope this work for you gyus too.