Why can't I turn on Microsoft Defender?

idgat said:

Uninstall MBAM and re-install

Uninstall using RevoUninstaller (freeware) making sure ...
- after the uninstall, DO NOT restart even if prompted
- choose the Advanced option to clean out leftover files, folders and registry entries
- reboot Windows
- check Defender to make sure everything is turned on
- re-install MBAM, LOOK FOR any option that offers a CUSTOM INSTALL (don't just click OK > OK > OK > OK > OK without reading what that step will do
- make sure that offending setting is turned OFF
- if it is not offered during install, don't reboot even if prompted
- go to settings and turn that offending option OFF
- then reboot

Those instructions can make things worse. Only the Malwarebytes support tool should be used.

Download the Malwarebytes Support Tool.

Please close all browsers and programs before running the tool. Right click and quit MB from the system tray also.
Once done it will attempt to reinstall both Malwarebytes and Privacy VPN.
Please say no and close the X button on the top right for Privacy.

I *NEVER* trust any 3rd party prorietary product with the term "Support" (or "Uninstaller", or "Cleaner" or ... etc.) in the same name as that proprietary product.

And, no, it won't make it worse. RevoUninstaller (and GeekUninstaller) are as close as perfect to completely uninstalling any program, than any so called proprietary "support" program. I'd much rather rely on a "4th party" uninstalling product with no vested interest in leaving leftover hidden traces behind.

The support tool deals with 2 main issues,
The self-protection module of Malwarebytes and licensing of the product. that Revo and Geek uninstallers can not do.