I can't believe we missed this post, sorry jim02.
(quick check) make sure that the fan on your processor/
cpu is still spinning in your case. This problem could be caused by over-heating.
Next try this:
When the computer starts to come to life, start tapping the F8 key on your keyboard. Eventually this will bring you to the Advanced Boot Options screen. Use the arrow up/down keys on your keyboard to select the option which says "Last known good configuration". Depending on the speed of your computer, this may take up to several minutes. This will restore that last good copy of the Windows registry.