1

Noticed for a while my Windows 7 PC had become very sluggish, specially when playing videos. Task manager showed the main Avast process consuming CPU at a constant rate of 20 - 25 percent. Finally traced it to the Web Shield module. I have now turned that module off and the improvement in performance is very noticeable.

2

Bit more nuance to the issue, what is causing it are the “Enable Web Scanning” and especially “Use Intelligent Stream Scanning”. I guess it is fine on higher end performance laptops but not on my Windows 7 machine.

3

Turning off Webshield kills your protection when you’re on-line. Not a good idea.
How much ram does your computer have ???