Please excuse me if I posted this in the wrong place. I just installed Windows XP Home Edition SP1 on my old computer with a 800MHz processor and 384MB RAM. I still need to install SP3, but after I install SP3, I was wondering if there is any good real-time security software (free) that will work good on a old computer and not slow it down too much? I use Microsoft Security Essentials on all of my other computers and it works very well. I also use Malwarebytes and Spywareblaster on all of my other computers. Would MSE slow down my old computer? Or should I just go with no security software and use just Malwarebytes and Spywareblaster?
P.S. I've already tried Linux on this computer, and I found that it isn't much faster than XP, so I don't want to use Linux.