Provider Error on Vista ultimate 64bit

I using avast home editon on my vista ultimate 64bit SP1
it success and work, i have check the scan log, the protection engine is working.
But on windiw vista control panel => Security Center , it say Avast haven’t start, when i click the [Turn On] Button, after few second,
it have a error popup and say the provider error.

then i uninstall avast and install AVG
it work and no any security warning message
so i uninstall AVG and install avast again, but it still not work.

I have search around the forum, it seem Windows Defender is possible block avast , but is it any thing to do make Windows Defender and avast work together?

Hi…

What AV did you use prior to your first installation of avast? I haven’t heard of Windows Defender and avast having any conflicts, although that doesn’t mean it hasn’t happened. ???

Best Regards…