Do antivirus software slow down the system?

I'm using Avira Antivir. I never felt my pc being slowed down by using it. But my PC does take a little while to start up. It will show the dektop quite fast, but would take a few seconds till it gets smooth. Some how disabling the network card solves the problem. So I don't think it's related to antivirus.

I think, yes, the antivirus makes the computer slow.

The line I read in an article long ago which I liked was something like "Having an antivirus is just like having a bomb sqad inspecting a suspicious package right next to your house"

And that's really true, they slow down the machine, and the biggest problem is when someone has a lots of data and when it's not defragmanted.

And there are simple ways to protect yourself, without using any antivirus.
Serious fact is that, most of the antivirus (even those top notch) are unable to detect the virus and trojans, if done a little tweak. So, what's the purpose of having them. I prefer not to install any, and if I'm downloading something, that may seem suspicious (but is really important to download) then you may just check it from virustotal.com it would check the signature of viruses with 46 antivirus programs.

Plus, don't ever download anything from any suspicious file, keep checking your running processes from time to time, would help in ensuring clean and secure system.

Does anyone know the 'technical stuff' that makes the computer slower; if it does?

Kaustubh KatdareDoes anyone know the 'technical stuff' that makes the computer slower; if it does?

I think it's due to the following reasons :-

a) It loads up on system start up
b) More data leads to more time in scanning
c) Some AntiVirus start scanning as soon as system starts up
d) The most important reason is, most of the antivirus have real time protection features such as for internet activities, and in many cases people often complain in their browser and connection lagging.

So, it's not that , it consumes memory only on start up , but it continuously occupies the RAM and keep running in background.

I also had experienced the slowdown of computer during the startup.Running many programs seems to be difficult and it consumes more processing power.

Any stealth virus have be a system process, that is why antivirus check for boot entries and modification by other process. This makes system startup delay.
If you observe once antivirus is loaded while startup, system start functioning as normal speed.
2nd, thing make your Antivirus slowdown system is real protection. When you download a file it checks the downloaded file soon it finishes, you can see the delay between 100% completion and completing the process of download.
3rd, Whenever you open a directory it checks for changes and auto execute files. This one also you can observe when you have a virus in your file system. Antivirus normally doesn't do anything but soon you open the folder it quarantine the virus.

More number of installed programs and start up, slow the start up, simple equation.
I have 8 GB of RAM but still my start is very slow and system is kind of freezed up till the antivirus loaded. I tried every tweak but no solution. Finally I just hibernate the system every time.😀

If you don't have hibernate option in menu just run

Ctrl+r --> shutdown -h

Yes a antivirus in the system slows down it up to a instent because the every program running in background and on desktop uses the ram memory and divides the system will divides the ram memory for the different applications.so if a antivirus running in background will also uses a part of memory so for real time use we have less ram memory so the system will slow down.That's why microsoft make the windows defender advanced so by using it which is part of window itself and we don't feel the slower system and also gets the security so use it friends.