os keep sthuting down after installation

I try to install routerOS on a system, after the installation the system keep shuting down. please what could cause it?

which RouterOS version did you install? did you apply a license?

Are you running on routerboard hardware?
If yes, did you upgrade firmware bootloader?

http://wiki.mikrotik.com/wiki/How_to_keep_my_router_up-to-date