Hardware connections are the first thing to be checked when an operating system fails to boot. Weak cables, broken hard disk, or broken RAM always seem to fail to boot to their start up functions. Confirmation of such parts allows establishment of whether the issue is physical and then proceeds with troubleshooting of the software.
Safe mode is a good way to get the software problems diagnosed. Safe mode can be used to boot onto only required files without loading drivers and applications which can create conflicts. Such a controlled environment gives an opportunity to find the problems that were run by latest updates, by installing some software, or by errors of the drivers without other system processes getting in the way.
The other method is the use of inbuilt repair tools. Startup Repair on Windows, or Recovery Mode on macOS are examples of utility programs that identify and automatically repair boot issues. They check system files, reassemble broken setups, and emulate missing components and minimize the use of complicated manual procedures.
When fresh changes result in malfunctions with the system, it is advisable to revert to a past stable status of the system. Utilities such as System Restore or Time machine allow the reversion of files and settings back to a previous date. This eliminates updates or installations which are incompatible and restores data, in essence restoring the system to its optimal condition.
The other methods may fail therefore you may need to reinstall the operating system. A clean install removes bad files or fatal errors that can not be correct with some repair programs. It is vital to data integrity to backup important data before reinstatement, having a fresh start and the full system functionality restored.
Conclusion
When dealing with a boot failure, it is necessary to debug the matter methodically. Hardware checks, safeboot, application of repair tools, system restoration and operating system re-installation are other important procedures. Using these methods guarantees that problems are detected and addressed effectively, with minimum data loss and restoration of budgetary functionality to the system.