I to am getting this error.
It happens when I try to start Avast4 by clicking the icon on the desktop, or selecting either of the .exe's in the program menu.
There are is no icon in the taskbar.
There are 2 avast exe files running as shown in task manager.
Neither of the processes can be stopped by task manager,
Durring install I get a warning:
___________________
Setup found another AV program. ETC
Norton AV / Internet security.
Do you wish to continue?
___________________
I have to select yes 2 times before it goes away.
I have downloaded and run (5 times) RNAV2003.exe.
I have scoured the registry for traces of NAV also.
I have run AVClear4.exe to remove Avast4 many times as well.
There are no programs running during install.
System is running Win2K SP3 on P4 3G with 1G ram.
Attempting install of PRO version.
Is there further information that would help?

can you tell me what/where the install file is looking for other AV's?
Cheers
Steve