Ok Barry, DX is here to help.
I had this similar issue on one of the laptops over here. Run through these troubleshooting steps to help me understand what the problem is.
First of all see if you can into Safe Mode. To do this when you boot up your system press F8 to bring up the menu for the Safe Mode options. Pick the first one and see if it takes you to a login screen. Make sure if it does take you there to log into an administrative account.
Once you log in open up the DOS system. This is also known as "Command Prompt". You can find this by typing "cmd" into your search area if your have Windows Vista or Windows 7. If using XP click on Run and type cmd into the Run window.
In the Command Prompt box type "sfc/scannow" without the quotes to do an integrity scan. If the system is not overly corrupt it will scan your Windows system for errors and attempt to repair it.
Do these steps first. If they don't work for you, please specify what doesn't work for you.
If this fails try the following:
If can load system in Safe Mode:
Open System Restore and turn your computer back to earlier Restore point. Depending on your computers activity, I have seen it able to turn your computer up to a month back in time. Restore it to a date before you had any issues. Once you start this process you can not reverse it, so any programs you had installed since that restore point may no longer be on your system. Your Music, Documents, Downloads, and Pictures will remain the same.
If unable to load in Safe Mode:
See if you can choose the startup repair option and boot the system with that. It should pull up a list of tools used for Windows Recovery. Choose the option to restore from a System Image. If there is no Image listed you won't be able to use this option.
Worst Case Scenario:
Reinstall the OS under clean install. If your computer is equipped with it you can press F11 or F12 to bring up the factory defaults menu and turn your computer back to the day it was first booted up.
The bad side to this is it will delete all your data and you'll have to re-setup Windows.
If you could please give me the following specifications so I may help you better.
Brand of Computer:
Model of Computer:
Operating System:
Have Factory Disc?:
Hope this helps you Barry please let me know. What has happened here is more than likely your operating system has a corruption prevented it from being able to boot into Windows properly. I ended up having to do a clean install on the machine I had the issue on because the OS was corrupted so bad there was no way to recover it. This usually happens when you catch a real nasty trojan.
Let me know how it goes,
Richard B. Williams (DXRenagade)