You uninstalled avast from which pc? Do you have more than one pc?
What is the O.S. on the pc that your having problems with? What is the O.
S. of the pc your using in the living room?
What version of Avast did you un-install?
If you can’t go anywhere on the Internet I doubt very seriously that it has anything to do with Avast causing that problem.
You say you can’t even boot up the pc that you un-installed Avast from?
I doubt that Avast is causing that problem.
I am sure there will be other responses with more pertinent information for you concerning this. Just wait a bit.