Sounds like a driver problem. Maybe the graphics driver is set to a resolution that the monitor can't display correctly.
Try booting into safe mode and uninstalling the graphics driver via control panel. Then boot normally and see if you can get into the desktop. If you can, then re-install the driver and you should be good to go. If the computer freezes even with the display driver uninstalled, then that leads me to think you have a hardware problem - specifically a graphics adapter problem.