Malwarebytes. Get the full version and let it run. ....
Under NO conditions would I connect a computer running Windows to the Internet without having a firewall and malware applications installed. Those should be added before the cable is plugged in or the wireless connection is logged onto. (Carry them in a USB stick from a protected computer.) Also, NEVER EVER suspend or disable the automatic update feature that Windows automatically runs. Updates from Microsoft do the following:
1) Fix bugs in software, making them run better or the way they are supposed to
3) Patch security holes in software that have been recently found and fixed.
Malwarebytes (the subscription version not the free one) is recommended by Steve Riley, author of
"Protect Your Windows Network Perimeter" and former Microsoft Security Guru. You can catch his postings on
KubuntuForums.net, where I persuaded him to replace me as a global administrator a couple years ago when I retired from that responsibility. That forum is not for Linux users only. Most of the admins and users also run Windows and any questions about Windows will be politely and graciously answered.
Malewarebytes should be set to automatically do a FULL scan your computer at least once every week, if not every night. Before running a Malwarebytes scan be sure to update Malwarebytes vaccine data file first. The latest vaccine file will contain the signatures of the most recently discovered malware. Having Malwarebytes set to run automatically (usually after midnight or on a weekend) will also cause it to automatically update the vaccine file. Running Malwarebytes without updating the vaccine file would be a waste of time.
Also, understand this: all it takes to change an old and well recognized piece of malware is to edit its source code and shuffle some of the lines of code around, without changing the functionality, or, adding new functionality, and then re-compiling it. Ta Da! A new virus that can escape detection by an AV product running with the latest vaccine data file. That's why Windows is attacked by as many as 2 million malware programs per year, or more. That, and the fact that Windows "ActiveX" technology automatically runs a program without asking the user, especially if the user got frustrated with clicking "Ok" on the User Access Permission popup and disabled it.
When an old virus is re-compiled or a new virus is created and the executable is distributed by email or the web, several thousand, or tens of thousands of users must get infected, and recognize they've been infected and send in a report and a specimen of the virus program to Microsoft or other security houses so that a vaccine can be prepared. A "vaccine" is just a line in the data file which contains the "signature" of the header of the virus executable. Until that signature is in the vaccine data and users update their vaccine data file and run the AV application, the personal information of the users is exposed to the undetected virus or Trojan. In the past Microsoft has been very laxed with AV security. Sometimes they won't fix a hole except by telling their customers to update to a newer version of Windows, thus using the vulnerability of their OS as an revenue generator.
Another BIG way to minimize infections is to stay away from those websites where the malware is as thick as fleas -- porn sites.