Windows slow down after installing AV !

You don't want to have two active (real-time) scanners going at the same time because they could conflict with each other and possibly cause your computer to crash. You'd need to temporarily turn off one of the real-time scanners before scanning with the other AV product. It's OK to use on-demand scanners because they won't conflict with your primary real-time AV program. Some of the free on-demand scanners are:

Malwarebytes : Malwarebytes Anti-Malware PRO removes malware including viruses, spyware, worms and trojans, plus it protects your computer

SUPERAntiSpyware.com | Remove Malware | Remove Spyware - AntiMalware, AntiSpyware, AntiAdware!

Hitman Pro 3 - SurfRight

You are asking for opinions.
Opinions are not always based on logic.
Most Security Applications are reviewed/ tested at intervals then made available for study.
These can be accessed via Google if you wish.
Remember quite often vested interests have a barrow to push so results may be slanted one way or the other.

You are the best judge of what suits you & your computer at any given time.

Have you thought of a layered approach for protection?
eg Eset, Malwarebytes, SywareBlaster....etc etc.

JMH said:

Have you thought of a layered approach for protection?
eg Eset, Malwarebytes, SywareBlaster....etc etc.

what do you mean plz ?

baxxter said:

JMH said:

Have you thought of a layered approach for protection?
eg Eset, Malwarebytes, SywareBlaster....etc etc.

what do you mean plz ?

As an example see links.... Read the "blurb" to see what they say.

http://www.malwarebytes.org/

SpywareBlaster® | Prevent spyware and malware. Free download.

Also note Post 31 recommendations.

Do you mean Eset, Malwarebytes, SywareBlaster ... have layered for protection ?Sorry my english isnt very good I mean I didnt get it well ?

You wouldn't happen to speak German?

PallasAthene said:

You wouldn't happen to speak German?

haha I speak arabic and french
Norton isnt like Eset, Malwarebytes, SywareBlaster ?

French? Okay, I've not spoken or written French for ages, but I'll try

J'espère que c'est d'accord si je me permets de te tutoyer ;-)
Alors, "layered protection" veut simplement dire: plusieures couches de protection pour ton ordinateur. En d'autres termes, tu as besoin de deux sortes de programmes de securité:
1) Un programme antivirus avec protection "realtime", comme Norton Internet Security ou Kaspersky Internet Security etc. Bref, une combinaison antivirus et firewall.
2) Un programme non-realtime, comme Malwarebytes.

Le programme non-realtime est installé pour servir comme protection supplémentaire, mais il ne fonctionne pas d'une manière automatique; tu dois l'activer et l'updater aussi - il n'a pas de fonction auto-update ou auto-scan.

Translation:
Just a small note: customers usually feel far more at ease if they can communicate in their mother tongue

I hope it's okay if I "you" you (languages like French and German have got two types of "you" - a politeness form (vous, Sie) and a less formal one (tu, du).
Layered protection simply means: several layers of protection for your computer consisting of basically two kinds of security programs:
1) an antivirus program with realtime protection, like Norton Internet Security or Kasperksy Internet Security etc. Briefly, a combination of antivirus and firewall.
2) An on-demand/non-realtime program like Malwarebytes.

The non-realtime program is installed as an additional layer of protection, but does not function in an automatic manner. It is you who has to activate/run it and you also have to update it, since it does not have an automatic update or scanning function.

thanks for translating :) I guess Eset smart security 4 is like Kasperskty or Norton internet security ?

De rien, je suis très heureuse d'avoir l'occasion de pratiquer mon français, ça fait assez longtemps...

Si Eset Smart Security inclut l'antivirus et un firewall en mode realtime - alors oui, ça corréspond aux suites Internet Security J'ai justement lu la description de Eset Smart Security - pas de problème, ça combine l'antivirus et le firewall.
En tout cas, je te recommande: une suite antivirus+firewall, et un programme complémentaire non-realtime comme Malwarebytes. Malwarebytes existe en français, tu peux choisir la langue pendant l'installation.

Translation:
No problem, I'm very glad to have the opportunity to use my French, it has been ages since I last used it...

If Eset Smart Security includes realtime antivirus and firewall - yes, that correspons to the Internet Security suites I just read the description of Eset Smart Security - no problem, it combines antivirus and firewall.
In all cases, I recommend that you use an antivirus+firewall suite, and an additional non-realtime security program like Malwarebytes. Malwarebytes exists in French, you can choose the language during installation.