No WiFi, constant crashes after downgrading avast

Ever since I removed Avast VPN (could not pay for the three services) and downgraded to avast free antivirus, I have no WiFi (despite it working on my other devices), I can’t uninstall avast without it crashing, can’t open anything without it crashing. All this happened right after removing Avast. Nothing is working cause it crashes every time. I’m at my wits end right now. I can’t afford to have somebody else fix it. I need help.

  • Which Avast…? (Free/Pro/IS/Premier)
  • Which version…?
  • OS…? (32/64 Bit…? - which SP/Build…?)
  • Other security related software installed…?
  • Which AV(s) did you use before Avast…?