For decades, Microsoft has embedded a secure mode into its Windows operating systems. This startup method makes it possible to analyze and fix system-critical errors even if software problems are at fault. For example, if the dreaded blue screen error message shows up immediately after starting up the operating system in normal mode, and nothing really works anymore, then safe mode can help. Booting in safe mode means that you’re only able to access the most basic processes. In other words, Windows no longer loads programs via auto-start, but instead uses only standard drivers and minimizes the use of the registry.
In this way, many possible sources of the error are already eliminated. This means that safe mode lets you locate the exact cause of the error, for example, by manually loading various programs that are normally activated directly when the system starts up. If you’re able to find the cause of the system crash using this method, you can also repair the system using safe mode in Windows 7 or uninstall the problematic programs. Once you’ve done this, starting up the system should work as usual even in normal mode.