Monitor problem

[dude1x2]

I am having a core 2 duo, Nvidia 7300Gt graphics, 1024 DDR2 ram,
When my system boots up, first the Xp symbol shows up and when it is time to go into the OS my monitor goes to stand by mode.(Monitior is LG L1752S)
Then after rebooting many times, maybe even rebooting from safe mode , I enter the OS. Can any one help me???

 

[ilugd]

check if the cables in your computer are not loose. Especially the harddrive cable and such.
Does the system beep or something like an error code?
Does it boot ok into command prompt?