<setuplauncher.settings>
<launcherextension>WarningMsgOp.dll<'/launcherextension>
<setup>
<program>NDP40-KB982638-x86.exe<'/program>
<parameters>'/q '/norestart<'/parameters>
<'/setup>
<postwarningmessage>If you choose to reboot, you must log-in under the same user name. <'/postwarningmessage>
</postwarningmessage></parameters></program></setup></launcherextension></setuplauncher.settings>
Or something like the above. If you execute the post warning message within the setup launcher settings, it gets displayed behind, so if you execute it directly after the setup settings dialog, then it will display on top, since it the last statement executed.
Oh, and don't forget, spelling counts.