On Troubleshooting tab of settings you can disable the windows and messages.
To full disable avast, right click the ‘a’ blue icon and choose ‘Stop On-access protection’.
More than this is not for begginners… Are these options enough for what you need?
I can’t understand what do you mena by ‘allow only one program’…
You can ‘disable’ avast antivirus right clicking the ‘a’ blue icon and choosing ‘Stop On-access Protection’ option…
If he is talking about ignoring the games program and allow it to run without intervention by avast, like IgnoreProcess in avast4.ini, I’m not sure if this is possible for the standard shield or if web shield would be the scanning provider as it is an on-line game.
Even if it were possible to ignore the games program executable, the content to and from the on-line interface wouldn’t be included in that exception/ignoreprocess.