how to stop it upload ??cos it make my internet slow 
thx
Well, I’m pretty sure your upload speed would have a pretty low cap, and should not have much impact on download speed.
But mainly, that is probably the Web Shield working. It re-routes all your Internet traffic through it, thats how it scans things before they land on your PC. So it really is not up/downloading anything. It scanning what you are browsing (Youtube). The “upload” is the WebShield sending something it has scanned to your PC.
How slow is it making your browsing? Is only Youtube affected?
i internet only have 512k upload/1.5m download speed ,the problem im playing the online game,everytime i open the youtube ,the game will very LAG until DC.if i want to open the youtube + game ,i have to disable the avast .
so is’t have other way i can play game + youtube whitout disable the avast?
What game/site?