Troubleshooting Windows Defender or Endpoint Protection client

- Rename the Software Distribution folder on your computer

1. Stop the Automatic Updates service
   1. Click Start and search for services.msc, and then click OK.
   2. Right-click the Automatic Updates service, and then click Stop.
   3. Minimize the Services snap-in.
2. Rename the SoftwareDistribution directory as follows:
   1. Click Start and search for cmd, and then click OK.
   2. Type cd %windir%, and then press Enter.
   3. Type ren SoftwareDistribution SDTemp, and then press Enter.
   4. Type exit, and then press Enter.
3. Start the Automatic Updates service as follows:
   1. Maximize the Services snap-in.
   2. Right-click Automatic Updates service, and then click Start.
   3. Close the Services snap-in window.

- Reset the Microsoft antivirus update engine on your computer

1. Click Start and search for cmd, and then click OKand then right-click Command Prompt, and then select Run as administrator.
2. In the Command Prompt window, type the following commands and press Enter after each command:
   Cd\
   Cd program files\windows defender
   Mpcmdrun -RemoveDefinitions -all
   Exit
3. Restart your computer.
4. Open Windows Defender or
   Endpoint Protection, click the Update tab, and then click Update.
5. If the issue persists, proceed to the next step.

- Manually install the virus and spyware definition updates

• If you are running a 32-bit Windows operating system, download the latest updates manually at http://go.microsoft.com/fwlink/?LinkID=87342 (http://go.microsoft.com/fwlink/?LinkID=87342).
• If you are running a 64-bit Windows operating system, download the latest updates manually at http://go.microsoft.com/fwlink/?LinkID=87341 (http://go.microsoft.com/fwlink/?LinkID=87341).
• Click Run. The latest updates are manually installed on your computer.

Material completo -> https://docs.microsoft.com/en-us/sccm/protect/deploy-use/troubleshoot-endpoint-client