Hello. I installed avast on several windows xp sp2 computers. I unistalled it in one of them but it seems that I can´t reinstall again because I have to update to sp3 (for many reasons I dont want to do that). So, in the rest of my computers avast is working fine on xp sp2 but I can´t install it again in the one I need it.
I don’t know how you managed to install it on the XP SP2 systems as the minimum requirement is SP3.
I can’t recall what version that requirement came in avast 2015 (10.4.xxxx) or early avast 2016 (11.2.xxxx to 12.1.xxxx) versions.
Get it over and done with and install SP4 on those systems.
http://www.majorgeeks.com/files/details/windows_xp_service_pack_4_unofficial.html
Make sure the system(s) support the SSE2 instructions set.
If they don’t, forget about installing avast (or for that matter any other new av) as it will not work.
If you can’t/won’t upgrade from XP SP2 and you can’t install Avast i’d definitely recommend Panda as a replacement. I’ve been using it on my XP SP3 systems since October without any problems whatsoever. According to their home page it only requires XP SP2.
But what they don’t mention is that their detection is not good and that there are performance issues.
https://www.av-test.org/en/antivirus/home-windows/manufacturer/panda-security/windows-xp/
Besides that it is kinda useless to put a av on a system when there are a lot of security holes in the os that can be abused.
That is like a house where you put 10 locks on the front door while leaving the back-door and windows wide open.
Not to forget the security holes in the OS!
=Snake=
Maybe i’m looking at that site’s ratings incorrectly but the 2014 XP ratings seem to be similar for both products, as do the 2016 Windows 7 & 10 ratings. I didn’t see a 2016 XP comparison. Anyone using XP has to know their system is old and subject to weaknesses. I guess SP4 is better than SP3 and SP3 is better than SP2 but it’s still old and outdated XP. It’s not about having 10 locks on the doors because with XP there aren’t really any doors left on the hinges. It’s about having 3 or 4 holes in the roof rather than 20 holes in the roof. 
;D
If he upgrades then stick with Avast. If not he’ll need something that works on XP SP2. Personally I still like XP and prefer this decrepit computer to my Windows 8 and was-7-but-is-now-10 systems. I also like Avast, and I especially like this Avast forum, but I don’t believe Avast is particularly concerned about XP. Maybe other companies aren’t either, but I had problems with Avast on XP and I haven’t had problems since I switched.
You’re wrong, see: https://www.avast.com/windows-xp-antivirus
But what they don’t mention on that page that systems need to support the SSE2 instruction set.
Something they have silently added on other pages after I mentioned it several times on this webboard.
Hi, I would like to know how you were able to install the latest avast on Windows XP SP2?
I don’t recommend it because the Visual Studio v140_xp runtime doesn’t support windows xp sp2 and that’s why we don’t support it neither. I guess Avast 12.1 is the last one which can run Windows XP SP2 but it isn’t officially supported. Later version won’t start on such systems (because of runtime as I have mentioned already).
Thanks,
pm
I’m afraid Avast won’t work properly on XP SP2 anymore - not even the old versions that worked previously. The thing is that XP SP2 isn’t able to verify new SHA2 certificates - so most of the online services (such as reputation services, and subsequently DeepScreen) and even parts of the program UI (that are actually fetched from our servers) won’t work. I’m afraid that even if we wanted to keep obsolete certificates on our servers (which we don’t), we couldn’t - because the old certificates have expired or will expire soon, and it would be tricky to find someone to give us a new certificates with a complete SHA1 chain.
Can you elaborate on this? Which parts of the UI and why?
I can’t… the whole UI is pretty complex and has been changing quite a lot through the versions, so I have no idea what could be affected in which version.
But there are parts of the UI that are actually online content - for flexibility and easier updates.