How to determine what .NET Framework level is installed:

How to find the .NET version using Windows Registry

1. Select Start.
2. type Regedit
3. In Windows Registry Editor, select the following path:
4. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP
5. Select the main version key – for example, v4 or v4.0.
6. Select the Client key.
7. Check the Version string to determine the .NET Framework version.

How to check .NET version using File Explorer

1. Open File Explorer.
2. Browse to the following path:C:\Windows\Microsoft.NET\Framework
3. Explore the folder with the latest version – for example, v4.0.30319.
4. Right-click any of the ".dll" files and select Properties.
5. Click the Details tab.
6. Under the Product version section, confirm the version of .NET – for example, 4.8.4084.0.
   

Microsoft .NET Framework is a collection of programming codes required for applications built using the .NET Framework technology to function properly. Specifically, it consists of a common language runtime that manages various things such as memory usage when you execute a .NET based application, and a .NET Framework class library that contains a collection of reusable codes developers can benefit from during the application development process. Each edition of Windows may have different versions of the .NET Framework installed or enabled/disabled.

Windows 8 and Windows Server 2012:

• .NET Framework 4.5 is an operating system component that is installed by default.
• .NET Framework 3.5 SP1 is an operating system component that is not enabled by default. It can be enabled in Programs and Features.

Windows 8.1, 10 and Windows Server 2012 R2:

• .NET Framework 4.5.1 is an operating system component that is installed by default.
• .NET Framework 3.5 SP1 is an operating system component that is not enabled by default. It can be enabled in Programs and Features.

Sage 100 ERP require the Microsoft .NET Framework 3.5 SP1 to be enabled in order to install and function properly.

To enable .NET 3.5 SP1 on a Windows 8.x or 10 operating system, perform the following steps below:

1. Open Control Panel, Program and Features (or Control Panel, Uninstall a program depending on your view setting).
2. Click Turn Windows features on or off.
3. In the window that appears, check .NET Framework 3.5 (includes .NET 2.0 and 3.0).
4. Click OK. Windows will search for required files, or specifically, for Windows source files. This may take a few minutes.
   • If Windows finds the local source files (or files used to originally install Windows 8), Windows will finalize the installation of .NET 3.5. then Click Close to exit.
   • If Windows does not find local source files:
     • it prompts you to download required files from Windows Update.
     • Click Download files from Windows Update.
     • Windows will download required files and finalize the installation of .NET 3.5. This may take a few minutes. Click Close to exit.

To enable .NET 3.5 SP1 on Windows Server 2012 operating system:

1. Open Control Panel, Program and Features (or Control Panel, Uninstall a program depending on your view setting).
2. Click Turn Windows features on or off.
3. The Add Roles and Features Wizard window should appear. Review this information first.
4. After reviewing the information, click Next.
5. From the Select installation type screen, select Role-based or feature-based installation and click [Next]
6. From the Select Server Selection screen verify the correct server is selected.
7. Click [Next] on the Select Server Roles screen.
8. In the Select Features screen, click the triangle icon next to .NET Framework 3.5 Features to expand it. Checkmark the following options below. If the Add Roles and Features Window appears, click Add Features.
   • NET Framework 3.5 (includes .NET 2.0 and 3.0)
9. After checking the above selections, click [Next].
10. Click [Next] until you reach the Confirm installation selections screen.
11. On the Confirm installation selections page, verify .NET 3.5 features are on the list. You have two options:
    • If the source files for Windows Server 2012 are on the local computer, or if you are unsure, click Install.
    • If source files for Windows Server 2012 installation are not on the local computer, click Specify an alternate source path near the bottom of the screen and installation files and then click Install.
12. If the .NET 3.5 features were installed successfully, you should see a message confirming the installation was successful.
13. Close out of Control Panel.

For the automatic downloads to complete properly, your company policy must allow you to download files from the Microsoft website. If you
receive an error message, click Tell me how to solve this problem or log unto Microsoft's website and review Microsoft knowledgebase
article number KB2734782, titled .NET Framework 3.5 installation error: 0x800F0906, 0x800F081F, 0x800F0907.

Note: Alternatively, instead of going through Control Panel, you can use this command line to enable .NET 3.5. However, this option may not install all .NET components properly even if you receive the message that it was successful. You must 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. Note that the ":d:" part corresponds to the DVD drive letter where the Windows 8 or Server 2012 media is located.

dism /online /enable-feature /featurename:NetFX3 /all /Source:d:\sources\sxs /LimitAccess

For more information, see these Microsoft articles and links:

• How to enable .NET Framework 3.5 on Windows 8 in Offline Mode (Microsoft KB 2785188)
• Enable .NET Framework 3.5 by using the Add Roles and Features Wizard (Windows Server 2012 only)