I had that same problem recently, and forget about that fix that microsoft reccomends or re-installs too,yes a reinstall is a good idea for measure and file replacement, but this is a solution I came up with after 4 hours of this fix and that fix.
Once you your reinstall and the damm thing still won't reboot or if it does and hangs like a petrified bat, restart and go to safe mode,some machines have this as F8, and some have it different, but get it in safe mode.Once it boots up, and it will and should,go to msconfig,and choose diagnostic start up, this will take away all but the neccessary components needed to boot normally. Once this is done you may not have network or internet connectivity until you isolate the issue,so be prepared to deal with that for a bit and a frequency of rebooting to isolate the problem. Make sure you reinstall all windows files so that they are there if need be. You will be prompted at every boot to restart because you will have to okay all the changes made in msconfig,but don't reboot,make a list or take a screen shot of everything in the startup tab, and choose two or three at a time, making sure to reboot after each one, and following the steps mentioned before about not rebooting until the next change is made. I have done this, and it isolates what is causing the problem from a bootup stand point, and also will aid in finding the bad file or driver. After each boot,or if the machine does not boot after a setting is restored,uncheck the last item, and reboot and check event veiwer to see what the error was. I did this last night, and it was on my work machine from my office,so I had no choice but to find a solution or risk losing months of settings!
Good luck!