There are two primary legal sources.
: A package built for an older Windows build will corrupt your current operating system files.
Search for "cmd," right-click it, and select Run as Administrator .
The /LimitAccess flag forces DISM to use only the local source you provided, preventing it from trying to contact Windows Update.
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs Use code with caution. (Replace D: with the drive letter of your mounted ISO) . Common Installation Errors and Fixes
Open Command Prompt as Administrator (Search for "cmd", right-click, "Run as Administrator").
Once .NET 3.5 is installed, the .cab file is no longer needed. You can delete it to free up space (approx. 250–300 MB).
Target computers are kept offline for security or are located in remote areas.
The DISM tool can fail for several reasons. Here are the most common errors and how to fix them.