Alternative to AVG? My old PC can't cope with it

I've had AVG on my pc since i got the pc over 8 years ago. I know i need a new pc but can't afford one.
When AVG starts updating everyuthing else freezes until it's completed the update and sometimes the AVG update freezes so i have to restart pc.
.Is there another good antivirus that I could use that doesn't take so much memory? I have a Dell 4700 no upgrades
Thanks