Malwarebytes free is the most recommended, but you will have to manually run scans and keep it updated.
Free Anti-Malware & Malware Removal | Malwarebytes
https://www.malwarebytes.com/mwb-download/
I also keep an updated copy of the ESET Sysrescue offline scanner on a USB thumb drive. Its Linux based and excellent scanning and cleaning hard to remove malware, adware and viruses outside of Windows.
ESET SysRescue | ESET
https://www.eset.com/int/support/sysrescue/
How to use it:
How do I use ESET SysRescue Live to clean my computer?—ESET ...
https://support.eset.com/kb3509
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.