Windows tricked me into downloading an UNIDENTIFIED 1703/ CU update instead of allowing me months for MS to sort out all the bugs. Windows Defender Antivirus Podeavanja periodinog skeniranja. Create a new GPO, edit Goto Computer configuration preferences windows settings Registry. The (limited) Periodic Scan is in 1703 located in the 'Windows Defender Security Center' which many times over the past few days becomes no longer reachable, so the 'Windows Defender Anti-Virus options' is then NOT there!! Clicking on 'Windows Defender Security Center' will in these cases lead to and show an incomplete panel for LESS than 1 second, and then revert to the 'Windows Defender'panel (all of the above through Settings). GPO to enable Windows Defender periodic scanning. No WITH t runs fine with both Kaspersky AND RansomFree for hours or days after 1703/CU was installed, then periodically turns off Periodic Scan and itself! This new feature, Periodic Scanning improves system security by using Windows 10 built-in Windows Defender as an additional scanner if you have installed any third-party antivirus.

Windows Defender will run properly with both Kaspersky AND RansomFree (I uninstalled and problem persisted.

Windows defender periodic scanning