The Windows Security Center service can’t be started
1) Scan PC with antivirus
First of all, deep-scan your PC with your security software. This is to ensure that, it is not some malware, which is preventing your Security Center from running.
2) Re-enable Security center
Disable and then enable Security Center and see if it helps.
3) Enable it using Action Center
If your Security Center is disabled, open Control Panel > All Control Panel Items > Action Center and see if you can restart the Windows Security Service by clicking on the Turn on now button.
4) Ensure that these Services are enabled
If this does not help, type services.msc in Start Screen search and hit Enter to open Services Manager.
Here ensure that the Security Center service is started and set on Automatic or Automatic (Delayed Start).Also, ensure that the Remote Procedure Call (RPC) and Windows Management Instrumentation services are started and set on Automatic.
Action Center, previously known as Windows Security Center, monitors the security status of the computer. However, the related service is called Security Center service. The Security Center (WSCSVC) Service monitors and reports security health settings on the computer.
5) Check Properties of Security Center Service
Since the Service Manager is open, you may optionally open Properties of Security Center Service > Log On tab. Click Browse. Enter your computer’s name in the Enter the object name to select box. Click on Check names, and then on OK/Apply/OK. See if this helps.
6) Repair the WMI Repository
Repair the WMI Repository, and see if it helps. To do so, open an elevated command prompt windows from the Windows WinX menu, type the following and hit Enter:
If you get a WMI repository is consistent message, you may skip this step. But if you get a WMI repository is inconsistent message, you can reset or repair the WMI repository. To do so, type the following and hit Enter: You will see a WMI repository has been salvaged message. Now see if it has helped. The Windows Security Center uses the Windows Management Instrumentation or WMI to collect information about the PC. If there are some inconsistencies, the Security Center may fail to start.
7) Run System File Checker
Run System File Checker to check for and replace corrupted system files if any, and see if it helps resolve the issue.
8) Use Microsoft Fix it
Microsoft Fix it 20084 for Windows 7 and Windows Vista will fix your registry keys and reset Windows Security Center settings to its defaults. See if it helps. I am not sure if it will work on Windows 10/8 too.
9) Troubleshoot in Clean Boot State
If this does not help, you have to perform a Clean Boot and troubleshoot the conflicting program which may be preventing the Security Center from running.
10) Reset Windows 10
If nothing helps, you may have to Repair Windows 7, Reset Windows 8 or Reset Windows 10. Do remember to create a system restore point first before making any changes to your system, so that you can always go back if the changes are not to your expectations.