This is the solution for users who are facing problem in dot net framework installation
Dot Net ONLY for Windows 7
https://filehippo.com/download_dotnet_framework_4/13065/
a: Click Start > Run.
b: Type cmd and press Enter.
Please run the following command in the opened window.
net stop WuAuServ
c: Click Start > Run Type %windir% and press Enter.
d: In the opened folder, rename the folder SoftwareDistribution to SDold.
e: Click Start> Run type cmd and press Enter.
Please run the following command in the opened window.
net start WuAuServ