William, the first thing you can try to do is to start windows in safemode. Once your computer boots up, right after your BIOS displays, hit the F* button a couple of times. That should bring up a start up menu where you can select how to start Windows. From here, I'd select Safe Mode (either with or without networking) and hope it starts up in safe mode. It will tell you that it is in Safemode. Once Windows is up and you see your icons,
select start
select control panel
select system
select hardware
select device manager
you should not have a window pop up that shows all your computers hardware installed. Check and see if you have any that have a yellow question mark. You could try to uninstall those by right clicking on them and select uninstall. Windows "should" find them again when restarting.
If none of the devices show a yellow question mark, make the assumption that you have no error here. Exit out of that. Hit Start
select All Programs
select Accessories
select System Tools
select System Restore
Once you select System Restore, it will allow you to (I know it's obvious:-) to restore your system to a point where you definitely remember the computer starting into windows without any problems.
The other thing that you should do, run a Virus and Malware check on your computer to make sure you are not infected. Hope this gets you started. Let us know if any of this is working for you, so that we can continue to help you out. Good Luck