force reboot post installaton

I want to force restart my installer post successful install. by having reboot in onInstSuccess , i can reboot . But it options (snapshot attached) as Reboot now or later. Even when i click on later, it reboots. I dont want any options. it should always force reboot post-install without giving any options like reboot later or reboot now.
any help is much appreciated.

i have set SetRebootFlag false in .onInstSuccess and flipflopped true/false with no positive results

Do you still want to show the finish page?

i resolved it by using !define MUI_FINISHPAGE_NOREBOOTSUPPORT and SetRebootFlag false on init