exception breakpoint being reached in installation

When I was installing the Pro upgrade, there showed a message “dllhost.exe - Application error. A Breakpoint has been reached . (0x80000003) occurred in the application at location 0x77b4367f.” I could not shut the dialogue box. When I ignored the message and tried to run Avast, another box popped out, “C:\program files\AVAST software\avast\avastUi.exe. one ore more arguments are invalid.”

I’ve tried reboot several times, uninstalled it in safemode, and re-installed it in normal mode. But the same messages kept popping out.

Anyone could help? Thank you!

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