[dartho]

With installed products, if it has an option to enable/disable it, you need to find the variable that corresponds to this and then you can set that accordingly.

For example - if an add-on has an option "Enable This Addon", search the xml product file for "Enable This Addon" - you'll find this in teh phrases section - check the phrase name - it will start with "setting" and end with "title" eg. setting_enable_this_addon_title. The variable name will then be enable_this_addon

You can then add a line in teh disable addons code area of:
$vbulletin->options['enable_this_addon']=0;

Be wary that the add-on author may have posed teh question "disable this addon" - in which case we would have.

$vbulletin->options['disable_this_addon']=1;

There are other ways to disable products that don;t have a global enable/disable switch, but it's a bit of a manual process or wrapping conditionals around plugins.