Enable .NET Framework 3.5 and 4.5 on Windows Systems

Summary

This article explains how to enable Microsoft .NET Framework 3.5 and verify installed versions on Windows systems. It also covers requirements for Sage 100 and how to check existing .NET Framework versions.

Resolution

CAUTION:

This solution needs advanced Operating System knowledge. Consult your system administrator for
help. Sage isn't liable for issues caused by improper changes to the Windows Registry. Always back up your data
before applying advanced solutions.

   

Check installed .NET Framework version

Use Windows Registry

  1. Select Start and type Regedit.
  2. Open Registry Editor.
  3. Go to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP
  4. Expand version folders such as v4 or v4.0.
  5. Select Client.
  6. Check the Version string value.

Use File Explorer

  1. Open File Explorer.
  2. Navigate to: C:\Windows\Microsoft.NET\Framework
  3. Open the folder with the latest version number.
  4. Right-click any .dll file and select Properties.
  5. Select the Details tab.
  6. Review the Product version section for .NET version.

Understand default .NET versions by operating system

Windows 8 and Windows Server 2012

  • .NET Framework 4.5 installs by default.
  • .NET Framework 3.5 SP1 exists but is not enabled.

Windows 8.1, Windows 10, and Windows Server 2012 R2

  • .NET Framework 4.5.1 installs by default.
  • .NET Framework 3.5 SP1 exists but isn’t enabled.

Enable .NET Framework 3.5 on Windows 8, 8.1, and 10

Use Control Panel

  1. Open Control Panel, select Programs and Features.
  2. Click Turn Windows features on or off.
  3. Select .NET Framework 3.5 (includes .NET 2.0 and 3.0).
  4. Click OK.
  5. Allow Windows to locate installation files.

If prompted for files

  1. Click Download files from Windows Update.
  2. Wait for the installation to complete.
  3. Click Close when finished.

    NOTE:

    Installation completes faster if Windows finds local source files.

     

Enable .NET Framework 3.5 on Windows Server 2012

Use Add Roles and Features Wizard

  1. Open Control Panel, select Programs and Features.
  2. Click Turn Windows features on or off.
  3. The Add Roles and Features Wizard will open.
  4. Click Next until you reach installation type.
  5. Select Role-based or Feature-based installation, then click Next.
  6. Confirm the correct server selection.
  7. Continue to Features.
  8. Expand .NET Framework 3.5 Features.
  9. Select .NET Framework 3.5 (includes .NET 2.0 and 3.0).
  10. Click Next, then confirm installation.
  11. Click Install.

If source files aren’t available

  • Select Specify an alternate source path.
  • Provide the Windows installation source location, then install.

Enable .NET Framework 3.5 using command line

Run this command from an elevated Command Prompt: dism /online /enable-feature /featurename:NetFX3 /all /Source:d:\sources\sxs /LimitAccess 
  • Replace "d:" with your installation media drive letter.

CAUTION:

This option may not install all .NET components properly even if you received the message that it was
successful. Verify in the Turn Windows features on or off screen that .NET 3.5 and its required
components such as the HTTP or Non-HTTP Activations were installed successfully.

 

Enable .NET Framework 4.5 or later

  • Windows 8.1 and Windows 10 include .NET 4.5 or later by default.
  • Enable it using Turn Windows features on or off if disabled.

Handle Windows 10 Anniversary Update issues

  • Some updates disable .NET Framework automatically.
  • Re-enable it using the same Windows Features steps.

Resolve installation errors

  • Ensure your policy allows downloads from Microsoft Update.
  • Review Microsoft article KB2734782 for common installation errors.

 

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224924550063629
Last Modified Date
Thu Jul 02 17:55:47 UTC 2026
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