How to temporarily block the installation of the .NET Framework 4.5.1 and its corresponding language packs

Important
Follow the steps in this section carefully. Serious problems might occur if you modify the registry incorrectly. Before you modify it, back up the registry for restoration in case problems occur.

To temporarily block the offering and installation of the .NET Framework 4.5.1 in an environment in which the Automatic Updates feature is enabled, follow these steps.

Note We recommend that you do not block the offering and installation for a long time for security, stability, and servicing reasons.

1. Back up the registry.

2. Start Registry Editor. To do this, click Start, click Run, type regedit, and then click OK.

3. Locate and then click to select the following registry sub key:
   HKEY_LOCAL_MACHINE\Software\Microsoft\NET Framework Setup\NDP

4. After you select the subkey that is specified in step 3, point to New on the Edit menu, and then click Key.

5. Type WU, and then press ENTER.

6. Right-click WU, point to New, and then click DWORD Value.

7. Type BlockNetFramework451, and then press ENTER.

8. Right-click BlockNetFramework451, and then click Modify.

9. In the Value data box, type 1, and then click OK.

10. On the File menu, click Exit to exit Registry Editor.

Note Organizations do not have to modify the registry in environments that are managed by using an update management solution, such as Microsoft Windows Server Update Services (WSUS) or Microsoft System Center Configuration Manager. Organizations can use these products to fully manage the deployment of updates that are released through Windows Update and through Microsoft Update. Computers that can directly connect to Microsoft Update can still receive the .NET Framework 4.5.1 unless the blocker registry key that is described in this article is deployed.