What are the risks in using Windows 7 without antivirus?

Although some people will suggest you that you can run Windows 7 operating system without any anti-virus. You are also correct that a heavy anti-virus will make your system to slow down. Even if you want to run your Windows 7 without anti virus, you cannot allow it to run naked. You have to configure your system which might not be an easy task for an ordinary user of a computer. If you do this, it will surely have some of its accompanied problems. When are using internet, we should not use Windows 7 operating system or with whatever the OS we use in our computer, we must have some sort of an antivirus to protect our computer fro malware and several kinds of viruses which keep on developing. There are several easy to run free anti-virus programmes available on internet like Quick Heal, Avira, Avast etc. If you use licensed and genuine Windows 7, you can download Microsoft Security Essentials from the official website of Microsoft.

You can use windows 7 without antivirus if your window is genuine. But if you are using a pirated window then there me be some problem in saving it from virus. You need to install some anti virus for protecting your computer from virus.
If you are using a genuine window and you are having an internet connection then Microsoft Security Essential is the best antivirus for your system. I bought my laptop in 2011 and since then I am using this antivirus and my laptop is completely secured. There is no need to waste money for buying any antivirus as you are doing so.
But if you are using a pirated window i.e. your window is not genuine, then this software will not install in your window. Then you can try various free antivirus software which are available in various software websites. But these antivirus software are not completely free. You can use them for a valid period of 15 days or one month and after that they expire and ask you to buy it. But you can find completely free antivirus software in the blogs of hackers. These hackers create a crack for the antivirus and it become completely free even after the expiration of the trial period.

One can use windows without having any antivirus.We can live without eating for 3-4 days then why do even we eat? To get nutrition and increase your immunity..right?
Similarly to make your System healthy and runnable you ought to have an antivirus.Antivirus is the immunity of the system.Simply use Microsoft Security Essential(its freely available) if you have a Genuine OS.

Regards
Ranjan
MWC 2013-Leaks and updates!

Hi Zanib,
If you want to use your system without anti-virus, then you need to follow some rules strictly. You should not use pendrives. That will make harmful threads to your system. Process only secured websites, so that your system would be protected. If the system is single handedly used, then you need not to worry about harm in your system. Keeping anit-virus in system and using that will make your system more secure. So that you could use pendrives without fear. Antivirus will protect from the threads. If any harmful threads going to attack your system, anti-virus would protect you. So the choice is yours. Whether you going to use your system with the help of anti-virus or without anti-virus is now your choice. I prefer using anti-virus is better option.

Using an antivirus program is always preferable. But the fact is that no antivirus software can detect all the viruses. That means though you are having an antivirus you can't say that your system is 100% protected. But yes antivirus programs surely increase the protection level. If your system slows down significantly after installing an antivirus then you may not want to install any. Not a big problem! Still you have an preloaded program, called 'Windows Defender' with Windows 7. Just update it regularly and it will detect many of the viruses and malwares also.

While accessing internet from antivirus-less Windows 7, make sure that you are using the browser with latest updates. If you are using Firefox make sure that you are using with "Private mode" enabled. In case you are IE user, make sure that you are using IE 9 with ActiveX installed. Though these can secure your system to some extent but it is not recommended to use any Windows OS without a good Antivirus with regularly updated virus database.

@ Ranjan: Your response is very nice but there is a common mistake in it and that is you haven't given space after full-stop (.). So please edit it and correct it.

According to me you should use anti-virus for a better protection against viruses because virus can attack you computer through internet, USBs, pirated CDs and DVDs. So, if you want your computer safe than you should install anti-virus in your computer.

"But education is still important because it opens the mind and expands it. And if your years in school were bad or boring you can still educate yourself now."

your system will be in danger without installing any antivirus so i recommend you to buy a good antivirus software to smoothly running your system, best antivirus software which i am using in my system is QUICK HEEL.
I hope this reply will be beneficial to you.