Windows 7 comes with the av from MS.
It can’t be removed, but it can be disabled.
So yes, there is besides avast a other av on the system.

  • Remove all folders/files from avast manually
  • Remove all entries pointing to avast from the registry
  • Reboot
  • Run CCleaner and/or the Glary utilities to cleanup disk and registry
  • Reboot
  • Install the latest version of avast (2016)