I know that everyone, okay ... almost everyone knows what antivirus and firewall are used for.
And it seems that one of them is on your computer. Everything seems to be good and there will be no trouble.
But suddenly you notice that the computer began to slow down (before that the computer worked quickly and well), the Internet began to work much slower, programs open longer than usual.
Be patient from the beginning, but everything is getting worse, applications stopped working, they do not start, they give errors.
And you started to notice that when you are doing nothing and you see that your computer is actively exchanging traffic ... a red diode or a green one is blinking, well, like someone:
There is a chance that your computer is infected with a virus.
I will add ...
Traffic is seen outgoing. BUT in the case of incoming traffic, there is a possibility that some program is simply downloading the update. This is fine!
And so ... it became clear to you that you have picked up a virus or a Trojan, or another bad guy from the Internet and especially from sites with naked girls, torrent, and other types of file exchangers.
Well, I have some kind of antivirus!
What's the matter!
And the fact is that somewhere you blundered ...
When you search for a program, antivirus firewall through a search engine, then in most cases you will receive a link to the official website.
Here you can download it from the official website (it is impossible to catch a virus in the distribution of the program downloaded from the official website)
But most of them want the PRO version (full), well ah trouble ... it is always paid, but ah how you don’t want to spread money!
And so you start searching through various social networks, torrent, etc. then it is highly likely that instead of a link to the official website, you will receive a link to a file exchangers like rapidshire, deposit files, etc.
It is precisely on such sites that the probability of downloading a virus is the highest, because the distribution kit is placed there not by the developers, but by hackers who, under the guise of a free version, add a virus or a Trojan program there.
As a result, you get a free program, and with it a malicious program that can easily either crash the system, or start infecting other computers on the network, or steal personal data such as passwords for various resources, credit card numbers, and so on.
And so ... I think it's clear that this is not the best option for your computer. But what if the finances are not good?
So we came to the main thing, a selection of the best and free antivirus and firewall programs.
Microsoft Security Essentials and Windows Defender
For the vast majority of home users of Windows 7 and Windows 8, a regular antivirus product from Microsoft is fine.
In the Windows 8 operating system, it is already built into a system called Windows Defender and does not need to be downloaded and installed.
But for Windows 7 you will have to install it by downloading the Microsoft Security Essentials distribution kit from the Microsoft website.
This solution is quite capable of protecting your computer from malware, has a very powerful basic functionality, and absolutely does not slow down the operating system.
That is why these solutions can be used as real-time protection on computers running Windows 7 and Windows 8.
Why are there third-party antiviruses and what's the point in them?
The answer is simple…
There are various categories of users, completely newbies who do not know and do not understand their actions. Antivirus should be handled knowledgeable ... for this you need to control all elements of the system so that your antivirus does not start to slow down the entire system.
Average users who have already got used to the computer and can quite distinguish between good and bad for themselves, no longer need the help of a friend.
Very advanced users want to control everything and not let the computer make any decisions on its own.
This leads to the need to install a powerful solution that will allow comprehensive control of the computer and allow it only those actions that the user wants to allow him.
Most of the time we are on the step ... average users. But Microsoft Security Essentials (for Windows 7) and Windows Defender (for Windows 8) are quite suitable and will cope with their tasks 100% without distracting us from work and without slowing down the computer.
In the case of Windows XP, the situation is worse ... you will have to look for an antivirus solution on the side.
And so download the free computer defender…. Microsoft Security Essentials
All antiviruses and firewalls in this article lead to official manufacturers' pages.
And so we continue ... a selection of the best and free:
Kaspersky Virus Removal Tool
Kaspersky Lab has a free anti-virus scanner, Kaspersky Virus Removal Tool, which will scan your computer and, if malware is detected, disinfect / delete infected objects.
The beauty of this scanner is that it is completely free.
But in order to use it with the latest anti-virus databases, it must be downloaded from the official website every time, since by itself it cannot update its databases.
It can scan your computer and rid it of malware. The program is updated several times a day and contains all the latest updates.
This can be a little inconvenient, because to get the latest version, you need to download a distribution kit of about 100 megabytes.
Although all this is justified free of charge and may well be used in critical situations.
http://www.kaspersky.com/antivirus-removal-tool
Dr.Web CureIt!
Doctor Web, which produces the antivirus of the same name, also has a similar solution called CureIt !.
With this curing utility, you can check and cure your entire computer without too much trouble. Each time you use the program, it is recommended to download its update from the website, since all anti-virus databases are built into the program and are not updated separately. Inconvenient!
This utility does not work all the time, preventing malware from appearing on the computer. It allows you to cure an already infected PC from viruses, Trojan horses, rootkits, etc.
This feature of Dr.Web CureIt! defines the scope of this product. It can be used periodically to check the reliability of the antivirus installed on the computer, as well as in cases when, by indirect indications, a computer infection can be suspected.
A feature of Dr.Web CureIt! is no need to install and update.
During scanning, Dr.Web CureIt! finds all infected files and disinfects them. If disinfection is not possible, the files are moved to quarantine (which will be available after scanning). After completion of the work, the program issues a report with the results of the check.
Dr.Web CureIt! does not conflict with other antiviruses, but works in parallel with them. Dr.Web CureIt! updated several times an hour. This means that it can detect even the newest viruses and Trojans.
http://www.freedrweb.com/download+cureit
Avara AntiVir Personal
The free version of Avira AntiVir Personal includes an anti-virus scanner, a module for checking and installing anti-virus database updates, and a module for real-time anti-virus protection.
This antivirus hangs in memory and does everything on its own. It independently downloads and installs updates, independently checks the files accessed by the operating system and various applications.
The free edition of Avira AntiVir Personal differs from its counterparts in the smaller number of additional protection modules.
For example, the free edition does not have an anti-spam module, there is no way to create a bootable recovery CD, there is no game mode, there is no built-in firewall and other modules that are present in paid editions.
Despite all this, Avira AntiVir Personal differs from its free competitors in that it does not need to be downloaded from the network every time, it downloads all updates by itself.
This is already a big plus. The only thing worth worrying about is the penetration of malware through loopholes that Avira AntiVir Personal does not close (due to the lack of additional modules).
However, some of these loopholes can be closed using other programs (the function of protecting the computer from attacks from the network can be entrusted to the COMODO Firewall program). And we download Avara AntiVir Personal using this snare:
http://www.avira.com/en/download/product/avira-free-antivirus
Comodo firewall (advise install )
It is a set of tools for protecting your computer, which includes a firewall, antivirus and active protection module.
If configured correctly, the program allows you to secure your computer to the maximum.
In general, this is a very good protection system that can protect your computer from external and internal threats.
http://www.comodo.com/home/internet-security/free-internet-security.php
avast! Free Antivirus
The program has a full-fledged Russian-language interface, it is quite difficult to get lost in it. You can get a key for it completely free of charge, for this you need to fill out a short form on the avast! ... is quite suitable for protecting your home computer.
Avast solves the problem of security in peer-to-peer networks. When using the uTorrent program and the like, a P2P screen is activated, which monitors unsafe connections within the torrent. 
The antivirus program avast! checks the system before a virus that has taken root in Windows is activated.
Users of slow Internet connections will greatly appreciate the reduced size of the antivirus update file. Updating takes less time and processor resources are used more efficiently.
http://www.avast.com/index
Results ...
Market leaders release only disinfecting utilities for free (this applies to Kaspersky Lab and Doctor Web) that can scan the system and cure it from viruses, but cannot provide full-fledged anti-virus protection in real time.
Antiviruses (Avast! And Avira) provide real-time protection functionality, but it is quite limited.
Here and the conclusion that you should not pass by the built-in Microsoft Security Essentials in the latest versions of the operating system, which is quite good and without load on the system copes with its protection.
Good luck to YOU, in two words ...ntivirus and firewall!
Good luck Friends!