Q: how to know when a new Antivirus has installed on windows I want to monitor the event of a new Antivirus installation , 
currently what I have in mind is listen to change in the Uninstall registry folder and then compare the new application name with a list of known Antiviruses.
I want to improve it by being more specific , is there other resource I can monitor in order to know when a new Antivirus has installed? for example some registry that new Antivirus have to edit in order to be marked as an active Antivirus etc.
Thank you for your help

A: Registry is not the best way. The information you want is usually exposed through the WMI.
Since you haven't specify in tags what language you're using, here's the link to the VBScript example. Beware that on 64 bit OSes there're effectively 2 WMIs, 32 bits and 64 bits.
If you want your software to react instantly, WscRegisterForChanges API allows you to be notified when the AV is started or stopped.
