This at first glance, sounds to be a display driver issue. As such, Start the computer, and tap the 'f8' key every half a second or so, untill you see a black screen pop up, with text on it. (NOTE: if you have a 'function' key, hold it down this will allow the F-keys to work). If the Packard bell logo disappears, but no black screen with text and you think it's loading windows, restart and try again. Especially with new fast pc's, this isn't' always easy to catch. If you get the screen, use arrow keys and navigate down to 'safe mode'. Then hit enter till somthing happens (usually twice). Eventually you 'should' see a logon screen, and if this works, log-on, and goto control panel, add/remove programs, and uninstall your video card drivers. Restart and normal mode should work, and then reinstall your video card drivers.
I'm hoping this is just a driver issue, let us know if this works! O one more thing, if you aren't sure about installing/uninstalling drivers, when you get to safe mode, you can always run system restore back to a time when your pc 'did' work.