Monitor shows out of frequency

:confused: :frowning: I had a Intel P4 2.6 HT pc with 256DDRAM. I installed solaris 10 with most of the default configuration by the system...now when i boot the system with solaris 10, after the boot screen is past and desktop login screen is about to appears the monitor goes down and displays "OUT OF FREQUENCY" message..
Can somebody suggest me wat could be done and is it happening....