I have had Avast for quite a while but today all of a sudden Windows Security Center will not recognise it and tells me I have no anti virus Program installed. Does anyone know how to fix this problem??
I have XP Professional with Service Pack 2 installed.
hi and welcome,
try reading this link and see if anything there helps you understand whats going on
http://forum.avast.com/index.php?topic=17589.msg150760#msg150760
good luck
Thank you Cloussau for your reply. I went to the link you provided,
absolutely nothing wrong with Avast ,working perfectly.
It was Windows, it had become corrupted when installing Apple Quicktime. I uninstalled Apple Quicktime and then ran sfc /scannow and everything is working well now. Thank you once again.
its my pleasure to be of assistance 
. one more bad apple ;D