According to Trend Micro, it has been confirmed that after applying “Windows 10 May 2019 Update” or after upgrading Virus Buster Corp., the Virus Buster Corp. client may repeatedly request an OS restart.
This is an event with the specification changes of the Window Defender.
For details, please check the following Microsoft information.
Reference information : Prevent changes to security settings with Tamper Protection.
Please note that the setting for Change the Tamper Protection setting shown in the above reference information will not be displayed until after uninstalling Virus Buster.