MSE is the least resource intensive free antivirus I know... avast will hog more
I found that symantec endpoint 12.1 uses even less resources than MSE, but your system is still quite below its system requirements

why don't you go try to find a used stick of ram? 512mb is so useless!

The computer is not mine anyway 😁

Slap a Linux distro on there.

Problem solved. (as long as you aren't concerned with forwarding viruses to others anyway heh)

I use MSE on my 512 MB Celeron (sadly, it's the maximum for those old Intel chipsets) and it works well enough most of the time.

Are you sure the installation of MSE did not trigger WGA somehow? Then again, I wouldn't expect problems with WGA to manifest as consuming all the available RAM, but it's something to consider.

How are you detecting that almost all RAM is being used on startup, anyway? Task Manager?

MSE usually is the answer for low-resource antivirus, but I have noticed that once in a while it will do this and eat ridiculous amounts of memory. For some reason it'll do that for a week or so and then stop completely... not that that is acceptable or anything.

I have used avast, avira and avg on 512mb- still snappy enough for normal use.

Though I must say, I recently "upgraded" one of my boxes- a P4 2.8Ghz with 640mb ram to Ubuntu 10.04 LTS and it runs very fast- with Compiz and all the bells and whistles enabled. A top flight O/S on a 9 year old PC- amazing.

I should add that I've tried Kaspsersky and BitDefender on this 512 MB machine and found them both quite intolerable.

According to Task Manager there are about 100MB of free memory,but the PC runs really slow. The hard disk is constantly grinding.

Linux is out of the equation. Besides I have heard of a new virus that is able to replicate under Win, Mac and Linux. I don't know if it's true.

I think I will leave it as is. I will tell the owner to get some more RAM.

avast with a custom install using only internet, behavior, and network scanners

eL_PuSHeR wrote:

According to Task Manager there are about 100MB of free memory,but the PC runs really slow. The hard disk is constantly grinding.

Maybe you can find out what is doing the grinding. Does Task Manager not show anything producing an unusual amount of CPU usage? What if you run Task Manager with Administrator privileges? Have you tried switching on the I/O Read Bytes and I/O Write Bytes columns? (You can do that from View->Select Columns.)

Also, is MSE in fact configured to run a scan automatically?

cdoublejj wrote:

avast with a custom install using only internet, behavior, and network scanners

That's exactly what I use, with avast 4.7. Make sure you get 4.7 because the later versions have this windows media player-like GUI that probably consumes more memory than crysis. (OK, 4.7 has this too but only for the scanning interface which you use maybe once a year.)

Thank you for your replies. I think I will leave it as is. I don't have too much time now for experimenting.

Hmmm what about Nod32 ? the "old" version 2.xx version ?

Avast 4.7 still works? I thought that was discontinued or something and keeps telling you to upgrade to version 6.
Nod32 2.7 would be ok, thats pretty lean on resources.

jwt27 wrote:

cdoublejj wrote:

avast with a custom install using only internet, behavior, and network scanners

That's exactly what I use, with avast 4.7. Make sure you get 4.7 because the later versions have this windows media player-like GUI that probably consumes more memory than crysis. (OK, 4.7 has this too but only for the scanning interface which you use maybe once a year.)

i'm guessing 4.7 still gets updates? i use the regular version on my main machines (6gb ram) and for 98se i use nothing.

You can disable the program updates right after installing and it won't ever know there's a newer version available. The virus database is still updated daily so I guess it uses the same database as the new versions.

Actually, the e-mail you get when you register contains instructions on how to insert the license key in version 4 and 5... but no mention of version 6 🤣

yeah, i guess that works.

Maybe Clamwin would be in order.

well clamwin doesn't have a resident scanner afaik so installing anything else and disabling all the resident stuff would work better maybe.