You can't avoid the alerts, but you man decrease the amount of alerts.
Here's how to do if you want to be secure, but still don't want 100s of alerts:
1. Open CPF, go to 'Security', 'Advanced', 'Misc.' and click Configure.
2. Set 'Alert Frequency Level' to 'Very Low', this should only generate one single alert per application.
3. In the same window, check the following check boxes:
'Do not show any alerts for the applications certified by COMODO'
'Skip loopback(127.x.x.x) UDP connections'
'Skip loopback(127.x.x.x) TCP connections'
4. Click 'OK', and now click 'Configure' under 'Application Behaviour Analysis' and uncheck everything except 'Monitor parent application leaks'.
5. Set Component Monitor to 'Off'.
This will give you some protection, but still not too many alerts.
If you want, you can add all programs your dad uses by yourself, so he won't have to worry about any alerts.