Hello, Bernie

As you said, two antivirus at the same time is not a good thing :-\

Seems ok. Anyway, please check 4 Registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\VirtualDeviceDrivers\VDD
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\Control\VirtualDeviceDrivers\VDD
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet003\Control\VirtualDeviceDrivers\VDD
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\VirtualDeviceDrivers\VDD

Do you see any Symantec driver there?
Is there a value for C:\ … path …\aswMonVd.dll?
If not, you’re in trouble at DOS under XP. Tell me and I can guide you through it.

The Home version allows only manual scannings.
You can schedule boot time scanning too.
With Windows Task Manager (scheduler) you can only use ashQuick.exe with some limitations.
Try the Profesional version. You won’t regard (I used NAV before ;D)

You don’t have to be sorry. Here is the wonderfull land for help 8)