I have a work computer running windows 10, and with the way win10 does everything for you under the hood I would like clarification/help on the following because it seems like I am at a point of this cannot be done and I find it hard to believe.

  • When installing 3rd party software and drivers for test equipment, it prompts saying .NET Framework 3.5 is required cannot continue- retry this install after you have installed .NET 3.5. And in win10 it conveniently pops up saying do you want to download from Microsoft.
  • The location of my win10 pc does not have internet connection and I am for the most part prohibited from an internet connection. I thought an offline install should be possible but...
  • is this correct: https://dotnet.microsoft.com/download/dotnet-framework/net35-sp1 which provides dotnetfx35.exe @ 231MB all that is needed?
  • In running this dotnetfx35.exe it still prompts to "Download & Install".

How does one do an offline install of .NET Framework 3.5?

from https://docs.microsoft.com/en-us/dotnet/framework/install/dotnet-35-windows-10

If you're not relying on Windows Update as the source for installing the .NET Framework 3.5, you must ensure to strictly use sources from the same corresponding Windows operating system version. Using a source path that doesn't correspond to the same version of Windows won't prevent a mismatched version of .NET Framework 3.5 from being installed. However, this will cause the system to be in an unsupported and unserviceable state.

that sounds bad, like I should not be doing an "offline" install?

  • 1
    For Windows 8 and above, .NET Framework 3.5 must be enabled from OS itself, which is a complex process itself involving possibly download from Microsoft server, or the original Windows installation media. Thus, dotnetfx3.5.exe installer won't help at all. You might contact the vendor of that software to ask for a .NET Framework 4.x compatible installer. .NET 3.5 was released more than a decade ago, so what would you expect? – Lex Li Mar 3 '20 at 20:42
  • I expect with the amount of money my corporation pays MS for windows, and what we paid for test equipment and software, it should be stated upfront an internet connection is REQUIRED – ron Mar 3 '20 at 20:52
  • 1
    Like I said, if you have the original installation media, internet connection should not be required. You should refer to relevant materials. BTW, "what we paid for test equipment and software" does not guarantee much if you check the relevant contracts. A piece of software requiring .NET Framework 3.5 strictly should have been made more than a decade ago, and in many cases end-of-life already. – Lex Li Mar 3 '20 at 21:21

If you have the install media, you can use powershell to install offline using the Install-WindowsFeature commandlet. Mount the .iso or insert the disc and then open powershell as an admin and run:

Install-WindowsFeature Net-Framework-Core -source d:\sources\sxs

where d: is the drive letter for the install media.

This microsoft article documents the method, though it is using a network share as the source instead of the install media.

Edit: An alternative method if Install-WindowsFeature is unavailable is Enable-WindowsOptionalFeature. Use the following syntax:

Enable-WindowsOptionalFeature -FeatureName "NetFx3" -Source d:\sources\sxs

  • I had forgot about this. This is the best answer. – Greg Askew Mar 3 '20 at 22:47
  • how do I fix Install-WindowsFeature in powershell or cmd returning program not recognized? This is a pc running win10 pro 1909 18363.418. – ron Mar 4 '20 at 14:26
  • @ron I added an alternative method that may work for you. please let me know if this is more successful – sippybear Mar 4 '20 at 22:38
  • I ended up physically carrying the stupid pc to a location to get online to accomplish this. I got fed up with trying to figure out Install-WindowsFeature not working on win10 pro. – ron Mar 5 '20 at 15:26
  • thanks for your help, It seems like it should work provided those windows server type of commands worked in win 10 home/pro. This is a major p.i.t.a. trying to get .NET 2.0/3.5 available for software that requires it, so far i cannot say it can be done without internet connection. – ron Mar 5 '20 at 15:28

.NET 3.5 is a builtin Windows feature. You need to run Add/Remove Programs, and click on Turn Windows features on or off:

enter image description here

  • i tried that, it does not work. It seems like doing this control panel add/remove feature simply kicks off the downloading of the required .NET files. I have no internet connection. – ron Mar 3 '20 at 20:39

Fire up an Administrative command prompt (not PowerShell).

Mount the original installation media.

DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:d:\sources\sxs

Where d is the mounted installation media you used to install Windows.


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