how can i fix my CRT monitor?

at first, the icons on my desktop were enlarged and then it went off, when it restarted again, after the microsoft logo came out, there popped all over the screen, "Sync. Out of Range." is something wrong with my resolution? i have a Samsung 17" monitor. i tried to connect another monitor into my CPU but it just remained black. When I connected the other monitor back into its original CPU, that monitor came to life again. Please help. Thank you for your inputs!