Is anyone having problems with Avast causing slowdowns with their video viewing? On one computer of mine, I get slight pauses in the video/audio when I’m watching. Also with a couple of sites, I’ve been unable to complete an order or purchase online. Everything is fine on my other home computer that doesn’t have Avast on it, and at work which doesn’t have it either. Is there some setting I need to change to make this work properly?
Concerning your ordering online problem try disabling or removing the avast browser protection ( AOS )
As for the video problem you haven’t given any information as to what player is used or version of avast installed and system type used on, also include other installed security software besides avast.
The videos are from YouTube.
And where is the rest of the information requested ???
Please remember that we aren’t sitting at your computer.
If you want help, please give us as much information as possible.
There may be some excellent people here but mind reading isn’t one of their specialty. 
I didn’t understand what you talking about?? Kindly mention here clear question with images or screen shot if possible