If you have access to another computer with internet, you can download the full offline package and transfer it to your offline machine via USB. How To Install .Net Framework 3.5 Offline On Windows 10
Enable-WindowsOptionalFeature -Online -FeatureName "NetFx3" -All -LimitAccess -Source "X:\sources\sxs" If you have access to another computer with
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs : Targets the operating system currently running. /LimitAccess : Prevents DISM from contacting Windows Update. If you have access to another computer with
This is the most common error. It means the DISM command cannot locate the microsoft-windows-netfx3-ondemand-package.cab file. If you have access to another computer with