i am not really too technical so i hope you understand my problems if i explain it as well as i can...
i have a windows sp2 on a 512 mb ram 1.8 gHz AMD sempron processor computer, with about 80% of the hard used. (it's a small 80 gb hard and yes i know i could do way better, i just haven't and can't afford any upgrades soon).
the AV is the avast home edition 4.8 and i also use windows firewall. i didn't install anything more since i am not sure what is good and what is not.
i've been having problems since saturday, the 9th (updates are automatic so i've no idea if there was a program update then or not).
problems are:
first, i had a "powerscan antivirus" popup unrequested on my firefox browser (which crashed immediately). since i've had a bad history with unrequested AV popups, i ran a scan on my c: and all it found were ALL the alwil software files (namely all avast files) that were infected with a trojan. at that point i got really scared, uninstalled avast, redownloaded, re-installed, updated the virus database and ran two scans.
one in safe-mode, after installing the AV - it found only one infected file - not an .exe file - (a trojan, it said) in the d: partition system restore files.
i am not sure if i did well but i disabled the system restore hoping to delete all files, then re-enabled SR.
then i did a second thorough scan, with archive scanning included, after entering windows. it didn't find anything more.
so this took care of the unrequested popups.
second problem: it takes forever since then to access the internet with firefox. i don't like iexplorer and i don't want to use it, i like firefox and i want to keep using it. but it takes a very long time to go online and also to browse pages once the browser is open. the main processes that strain the system are svchost.exe which seems to be running in separate locations for SYSTEM and NETWORK (i'm in a network so maybe that's ok but i'm not sure. avast is only installed on my computer, i don't know what the others have.) the processor hits 100% usage all the time and it's not really healthy for it.
reading through this thread i noticed that some users have disabled the archive scanning after doing the safe-mode scans so i've disabled it too to see if it makes any difference. so far i've seen none.
so what i wonder is this...
1. does the latest update make this happen? overusing the processor and slowing down my system??
it's getting annoying when even google won't show because of the long delays that cut the connection.
2. is it possible that by uninstalling the "positive" infected avast files i actually allowed a virus to spread and infect my computer? does re-installing and scanning in safe-mode provide a safety belt for this?
3. is it possible that a virus database used as an update was corrupted and made my AV go crazy on me?!
4. which online scan could i use to make sure the system IS clean and not giving me false good reads? i don't want to stop avast for an online scan by another AV, are there some good enough that wouldn't require stopping the running AV?
5. is it really the fact that avast was updated to fit with better, newer systems that's making it incompatible with my older and slower system?
sorry for all the questions. i am just getting really freaked out here.