Failure to start GUI
Sometimes, Windows won't be able to complete the boot process, but it won't generate an error, either. Instead, it will seem to hang at one spot in the boot process without going any further. You can deal with this problem in a number of ways.
The first action you might want to take is to see if the OS has loaded the networking components. If the networking services are running, then you may be able to connect to the computer using Computer Management or Event Viewer, which will allow you view information about the OS and read the event logs. There may be errors in the event log which will let you know what the problem is.
If you are not able to connect to the computer, then your only options are to continue to wait, or cycle the power on the computer. If the computer has locked up hard enough, then the soft power button may not work, and you may have to unplug the computer; if it is a laptop, you will have to remove the battery. This action, as with any power interruption, has the risk of causing corruption to the file system, and should be used as a last resort. On reboot, the system may boot properly, or you may want to use one of the F8 boot options, such as Safe Mode. Safe Mode would allow you view the Event Logs using Event Viewer, and that may give you insight into the problem. The F8 boot options will also allow you to create a bootlog, which if your next boot is unsuccessful, will let you know approximately where the failure is occurred. If you are unable to find the solution, disconnect all peripherals such as USB devices, and attempt to reboot the computer. If the problem is with a peripheral or its driver, then you may see a successful boot. In some cases, I have seen errors with peripherals occur after the system has successfully booted for years, and the problem can usually be traced to an OS update, a drive update, or file system corruption of the driver.
If you think you know what is causing the problem, perhaps a driver or service that won't start, then you could also use the Recovery Console to try to fix those problems.
