How to start Windows in safe mode.
Safe mode is a simplified version of Windows that can help you troubleshoot problems on your PC. If a problem doesn't reappear in safe mode, you can eliminate the default settings and basic device drivers and services as possible causes. If a recently installed program prevents Windows from running correctly, you can start your computer in safe mode and then uninstall the program that's causing the problem. When starting your computer in safe mode, it's important to know which files you're deleting and why, since deleting the wrong file could disable applications on your computer or your entire operating system.