In order to modify the MAXROWCOUNT limitation for reports and collections globally, modification of the ReportMaxRowCount value using NS Configurator is required.
If not installed, NS Configurator can be installed by executing .\Program Files\Altiris\Diagnostics\NSConfigurator.msi.Launch NS Configurator from the Start Menu on the Notification Server. Start > All Programs > Altiris > Tools > NSConfigurator
When the NS Configurator UI comes up (must be locally on the NS), search for rowcount and modify the value for ReportMaxRowCount. Set the value to 0 to disable the MaxRowCount.
Setting the value to something like 150,000 or an acceptable increased value to meet the needs is preferred to prevent runaway queries (aka. Cartesian products).
Apply the setting and the maxrowcount should now be disabled.