As of the latest versions, will it be OK to install Avast Free Antivirus, Comodo Firewall, and Malwarebytes Anti-Malware Free at the same time. I mean will there be any conflicts, system slowdowns etc if all three are installed at the same time.
Is this good protection for a medium risk PC user or is this too much… I mean three different products installed at the same time, perhaps I should leave one of them out or research more on the best free protection.
That should be fine, assuming you are only installing the comodo firewall and defence+ (not comodo AV).
The main issue is not having more than one resident AV installed. Generally the same is true of firewalls and anti-spy/malware applications.
Yes.
I currently use all three, and I have no problems.
And turn off Comodo sandbox IF you’re going to used Avast autosandbox, having both sandbox can cause conflicting between Comodo FW and Avast Free Antivirus 
Yes I will be installing comodo firewall and defence+ only (not comodo AV/IS) and I will keep the sandbox tip in mind, thanks.
I am migrating from kaspersky Internet Security by the way, never had much infection problems, just few days back KIS blocked a Trojan before it even got downloaded while I was web browsing, & this was the only incident in a long time. It’s heavy on resources though & I am running a slightly older PC (DDR1 512MB+P4 Prescott). Will miss good ol’ KIS.
You would want to use the KIS removal utility to get rid of any remnants after uninstalling it. Search for Kaspersky at http://thewebatom.net/uninstallers/security-software/.
This minimizes future conflicts with other AV.
I had already downloaded this, probably the same thing… kavremover.exe
http://support.kaspersky.com/faq/?qid=208279463
Will uninstall KIS & install Avast Free Antivirus + Comodo Firewall + Malwarebytes Anti-Malware Free, tonight since there doesn’t seems to be any mentioned problems. Let’s me hope it gives good PC protection without using too much resources as KIS did.
I think you will welcome the better overall system performance with avast, provided as advised you remove all remnants of KIS.
Welcome to the forums and the avast family ;D
Aren’t you able to upgrade the memory? Sorry it’s a bit off topic but since it’s a Prescott I would think you can probably go up to 1 gig, and if you paid for Kaspersky, even if it was free after rebate I would think the ram upgrade makes a lot more sense and is very inexpensive, especially used off eBay or something.
It isn’t the CPU that determines the memory limit but primarily the Motherboard (and the OS of course). That can be checked using a tool from crucial.com.