If you are trying to install .Net 3.5 via the Add Programs/Features on Windows 11 and get the above error, follow these simple steps:
- Download the Windows 11 ISO here
- Mount it (should be drive D, but confirm
- Run this command in an command window with administrator privileges, changing D for the drive letter where the ISO was mounted:
Dism /online /enable-feature /featurename:NetFX3 /All /Source:%setupdrv%:\sources\sxs /LimitAccess
