Apart from keeping Windows 10 up-to-date with Windows Update, in order to keep it secure and protected from attack, you also need to protect your own files and internet connection from Viruses, Spyware and so on. You do this by installing protection software that monitors your own files, Windows 10 files and your internet connection for anything that may harm them.
Protection Software needs updating regularly - Either once a day or once a week, depending if a new threat has been identified. For example: Most protection programs need a Definition (Database) File that tells them how to identify a known attack and how to cure a known attack. As well as how to identify, and possibly cure, unknown attacks based on history cases. A definition file may need downloading manually by you or automatically by the protection program. Either way, if the definition file is not downloaded regularly you will be in danger. Take this scenario:
If it is Monday 1st today and your Anti-Virus's definition file is up-to-date, it will only be up-to-date as of today (Monday 1st). So if you do not update it tomorrow (Tuesday 2nd) and the next day (Wednesday 3rd) you are still okay, as long as no new virus is unleashed on Tuesday 2nd or Wednesday 3rd. However. If a virus is unleashed on Tuesday 2nd or Wednesday 3rd you might be in trouble, because your Anti-Virus's definition file only knows how to identify and cure known viruses from Monday 1st and before that. So from here you have to hope and pray that your anti-virus program, and more importantly its definition file, can identify and cure the new unknown virus. By updating your protection software regularly you are not only defending the computer against past attacks, but you are also protecting it from new attacks that have been identified (and possibly cured) by the software developers and from new attacks that can be cured with educated guess work.
Below is a list of well known, commonly used, protection software that is absolutely Free-To-Download and Free-To-Use. They are all of commercial quality and usually paid for by sponsorship, donation or from sales of their PRO version. Some of them are genuinely FREE, but most are a way for the company or individual(s) to advertise their other software. Meaning: When you have seen what their FREE software can do, you might be interested in visiting their website to read about and possibly buy their PRO version. That said, the software titles listed below do not display pop-up advertisements of any kind - Some ask that you supply an e-mail address but this is only to register the software so that you can receive free updated definition files and/or special offers, and even then you are not bombarded with e-mails.
AVG Free is an Anti-Virus program that runs in the background constantly monitoring Memory, E-Mails and Files for Viruses. Many Magazines and Websites highly recommend AVG, as do I and millions of other users.
AVG needs its definition file (database of known viruses) updating regularly. Once a day or once a week, depending if there is a new virus spreading around. AVG connects to its server (definition files computer) automatically, at least once a day, to check if its developers have uploaded (stored) any updated definition file(s). If they have, AVG downloads and then installs the definition file(s) straight away. You can also connect to the server manually if you want to in order to check for any updated definition file(s). Clicking on any found definition file, from a list, will automatically download and install that definition file for you.
AVG Website AVG Download
Another Free (Personal Edition) Anti-Virus program is Avira AntiVir, which I recommend as a good alternative to AVG.
Ad-Aware provides protection from known Advertisers, Trojans, Dialers, Malware, Browser Hijackers, Key Logging Software and Tracking Components by scanning Memory, Fixed and Removable Drives (i.e Hard Drives, Floppy Disks, Flash Drives, Etc) and the Registry. If it finds any thing bad it removes it. Ad-Aware uses Code Sequence Identification (CSI) technology, which means it can make an intelligent guess if something is bad or not.
Ad-Aware needs its definition file manually updating regularly. Once a week should be okay.
Ad-Aware Website Ad-Aware Download
McAfee WebAdvisor is a piece of software that communicates with its internet service (knowledgeable database) to warn you of "social engineering" attacks whilst you are searching the internet. Websites and webpages that have such things as Spyware, Identity Theft and E-Mail Spamming ("social engineering") behind them are marked by WebAdvisor with either a green, yellow or red symbol next to their search result (linked website or linked webpage). A "social engineering" website/webpage normally attacks/infects your computer when you download software from it or fill out a bogus online application/registration form from it. So if you search for something with Google using Internet Explorer a green symbol next to a search result (linked website or linked webpage) means the search result's link is safe to use/enter, whereas a yellow symbol is a warning to be careful (use/enter with caution) and a red symbol means stay well clear.
Note well: WebAdvisor only works with Internet Explorer and Firefox and a key thing to note is that WebAdvisor concentrates its energy mainly on the first webpage. Meaning, if you click on a search result (linked website or linked webpage) with a green symbol next to it the first webpage you enter from clicking on that search result should be, fine.....because it was given a green symbol. However, the webpages linked from within that first webpage (internal links) might not be good. Even though WebAdvisor will try its best to advise you about all search results, and their internal links where possible, you must still apply general caution to the websites/webpages you visit. WebAdvisor is well worth installing.
McAfee WebAdvisor McAfee Free Services
SmitFraudFix can clean/fix the more serious problems found on a computer (i.e. Damage caused by Adult Websites), as well as a host of less serious problems (see the SmitFraudFix website for more information). This program is a MUST if you have serious computer problems and more importantly a life saver and computer saver. It's that good. Although this program is really for an Advanced User the website gives enough well explained instructions for you to use it.
SmitFraudFix has not been tested, by me, on Windows 7 or Windows 10 yet and the SmitFraudFix website does not state Windows 7 or Windows 10 compatibility at this time. It works fine on Windows XP though.
SmitFraudFix needs its definition file manually updating regularly. Once a week should be okay.
SmitFraudFix Website & Download
Spybot - Search & Destroy can detect and remove thousands of different Spyware threats (Advertiser and Tracking information), as well as clean the Registry of your Last Visited Websites keys, your Opened Files keys, your Started Programs keys, Cookies and more. It does this by using a definition file and its inbuilt protection technologies. The beauty of SpyBot is that it can immunize Internet Explorer, which means known bad websites are added to internet explorer's Restricted Sites zone so it knows to disallow those bad websites. For example: If internet explorer's Start Page has changed without you knowing you might have spyware. Or if spyware is gathering marketing information (your movements/internet habits) and SpyBot detects it, SpyBot will remove it.
SpyBot needs its definition file manually updating regularly. Once a week should be okay.
ZoneAlarm is a FireWall (Wall of Fire) that blocks/stops Hackers, Bad Websites, Bad Downloads and Unknown Threats from entering Windows 7 via its internet connection ports (entry points). Your internet connection is made invisible to hackers and so on.
Although ZoneAlarm systematically identifies hackers and so on and blocks their access attempts, occasionally it asks you if you want to ALLOW or DENY a program it knows nothing about. In these cases always DENY, unless you know the program is okay. For example. You might be installing a Printer one day and then the ALLOW / DENY requester pops up. In this case, you would probably choose ALLOW as you know you are installing a new printer program. But even if you DENY and then the printer does not work, you will definitely know you denied the printer program. So it makes good sense to always read the requester, as it normally gives information about the file in question. The best thing about ZoneAlarm is that it does not need definition files updating - It can be left to do its thing while you do yours.
ZoneAlarm Website ZoneAlarm Download
So which of the above programs do you need to install? Answer. All of them, except SmitFraudFix (emergency programs only!). Each program is different in the way it works, even if some of them are protecting your computer files in the same way.
ZoneAlarm, which continuously runs in the background, is regarded as a better FireWall than Windows 10's firewall. AVG Anti-Virus, which also runs in the background continuously, is regarded by Magazines and Internet Users alike as one of the best free anti-virus programs. SpyBot, which needs to be run at least once a week manually, is an excellent general cleaning program which can get rid of many different types of problem. Ad-Aware, which also needs to be run manually at least once a week, is added protection. It might find something SpyBot did not for example, purely because of the different ways both programs check for threats. Finally. SmitFraudFix, which I class as specialist program, should really only be installed when serious problems start emerging.
Although this goes against the argument, "Prevent it from happening by installing the protection software first", you can only have so much protection installed before your computer becomes over protected and slow. SmitFraudFix is more in the way of Clean-Up programs (after something has happened), whereas the other programs I have mentioned are general every day protection programs.
If you are looking for commercial software Symantec, who produce Norton Internet Security, and Bitdefender, who produce Bitdefender Total Security, are both recognized as the leaders. Both companies are producing other software, such as Anti-Theft and Family Protection, but the reason why I mention the above Free-To-Use software is because they tend to use less resources and less over-protective. They tend not to slow down the computer as much as Symantec and Bitdefener products.
Saying this, the commercial companies have recognised these controverses and made their softwares more system resource friendly. As to which is the best between Symantec and Bitdefender, I would say Symantec simply because it is not as over-protective as it was a couple of years ago and does not hog system resources like it used to. By over-protective I mean that Norton Internet Security for example sometimes blocks programs/websites you want to use and it is not always easy to know how to fix the problem (get into its settings so you can adjust them). This is purely because they are trying to balance your online safety whilst not allowing you to comprise it by messing up settings and so on.