For future reference, starting a new thread will usually result in a faster reply.
First you will need a Windows 10 install disc. If you don't have one, you can download it directly from Microsoft using the Media Creation Tool. (You don't need a physical disk, an ISO/disk image is fine.)
https://www.microsoft.com/en-us/software-download/windows10Mount the Disc (either by inserting the disk or opening the ISO)
Open an elevated command prompt and enter the following command:
Dism /online /enable-feature /featurename:NetFX3 /All /Source:D:\sources\sxs /LimitAccess
here D:\ refers to the location of your DVD/CD Drive. Check This PC to make sure you are using the correct drive letter.