More and more programs use Microsoft. NET Framework and Windows Update requires you to install the latest version. However, occasionally you may encounter problems when installing, updating or reinstalling. Microsoft provides an official solution but that doesent work at times, below is a little work around that does the job.
The simplest way to resolve this issue is as follows, Open CMD
1.Stop the windows update service
use this command ---> net stop WuAuServ
2.Rename the folder 'SoftwareDistribution' in your windows folder (most Probably 'C:\Windows\ SoftwareDistribution ') to something else like 'SoftwareDistribution_old'
3.Restart the windows update service
use this command ---> net start WuAuServ
4.Now try to install the .net framework again.It should now work smoothly.
You can download the latest microsoft-net-framework-45-windows-10