Startup problems can be divided into three distinct categories:

• Problems that occur before the Starting Windows logo appears. These problems are typically caused by missing startup files (often as a result of installing a different operating system over Windows 7), corrupted files, or hardware problems.
• Problems that occur after the Starting Windows logo appears but before the logon prompt is displayed. These problems are typically caused by faulty or misconfigured drivers and services. Hardware problems can also cause failure during this phase of startup.
• Problems that occur after logon. These problems are typically caused by startup applications.