Ralph: try this:

Restart, hold down F8 as the computer restarts and then start in the safe mode (highlight "Safe Mode" using your arrow keys and enter). Once the desktop has booted up, go to Start>All Programs>Accessories>System Tools>System Restore. Choose a date at least a few days back when your computer was working and the click "Restore." Allow the computer to do its' thing without touching anything! It should reboot itself.

You probably clicked on one of the spam "Speed Up Your Computer" or Your Computer Has A Virus" and they install a cooking that prevents you from getting past their starting window. System Restore should clear this for you.

Good luck

Rich