Troubleshooting Windows 10

Troubleshooting with alternative boot options

Before there was Reset, there was Safe Mode.

The recovery and reset options in Windows 10 make some traditional troubleshooting techniques less important than they used to be. Booting into Safe Mode, for example, used to be a mandatory step for recovering from problems. On modern hardware, with UEFI firmware and solid state drives, it’s literally impossible to interrupt the boot process to switch into Safe Mode.

If you can start Windows and get to the sign-in screen, you can then hold down Shift and click the Power button in the lower right corner of that screen. Clicking Restart while holding down Shift makes an alternative boot menu available, with some interesting troubleshooting options.

To get to the Startup Settings menu, open Settings, Update & Security, Recovery, and then click Restart Now under Advanced Startup. After restarting, you can tap Troubleshoot, Advanced Options, and finally Startup Settings to reach the blue, full-screen menu shown in Figure 17-12. The nine choices shown there (one additional option is on the next screen) allow you to start Windows in modes that make some forms of troubleshooting easier.

Figure 17-12 The Startup Settings menu lets you boot into Safe Mode to remove a troublesome program or driver that is preventing you from signing in normally.

The three choices in the middle enable Safe Mode, which starts Windows using a built-in administrator account, using only services and drivers that are absolutely required to start your system. The operating system runs with a generic video driver, with support for keyboard, mouse, monitor, local storage, and default system services. In Safe Mode, Windows does not install support for audio devices and nonessential peripherals. USB flash drives, hard disks, keyboard, and mouse are supported. All programs that normally run when you sign in (programs in your Startup folder, for example) are bypassed.

In Safe Mode, you can access certain essential configuration tools, including Device Manager, System Restore, and Registry Editor. If Windows appears to work properly in Safe Mode, you can safely assume that there’s no problem with the basic services. Use Device Manager, Driver Verifier Manager, and Event Viewer to try to figure out where the trouble lies. If you suspect that a newly installed device or program is the cause of the problem, you can remove the offending software while you’re running in Safe Mode. Use Device Manager to uninstall or roll back a hardware driver; use Control Panel to remove a desktop program or utility. Then try restarting the system normally to see whether your changes have resolved the problem.

One important troubleshooting tool that is not available in Safe Mode is Backup And Restore. To restore a system image backup, for example, you need to use the Windows Recovery Environment, not Safe Mode.

If you need access to network connections, choose the Safe Mode With Networking option, which loads the base set of Safe Mode files and adds drivers and services required to start Windows networking.

The third Safe Mode option, Safe Mode With Command Prompt, loads the same stripped-down set of services as Safe Mode, but it uses the Windows command interpreter (Cmd.exe) as a shell instead of the graphical Windows Explorer (Explorer.exe, which also serves as the host for File Explorer). This option is unnecessary unless you’re having a problem with the Windows graphical interface. The default Safe Mode also provides access to the command line. (Press Windows key+R, and then type cmd.exe in the Run dialog box.)

The six additional choices on the Startup Settings menu are of use in specialized circumstances:

• Enable Debugging. This choice starts Windows in kernel debug mode and requires a physical connection to another computer running a debugger.
• Enable Boot Logging. With this option enabled, Windows creates a log file that lists the names and status of all drivers loaded into memory. To view the contents of this file, look for Ntbtlog.txt in the %SystemRoot% folder. If your system is hanging because of a faulty driver, the last entry in this log file might identify the culprit.
• Enable Low-Resolution Video. This option starts the computer in 640 by 480 resolution using the current video driver. Use this option to recover from video problems that are caused not by a faulty driver but by incorrect settings, such as an improper resolution or refresh rate.
• Disable Driver Signature Enforcement Use this option if Windows is refusing to start because you installed an unsigned user-mode driver. Windows will start normally, not in Safe Mode. (Note that you cannot disable the requirement for signed kernel-mode drivers.)
• Disable Early Launch Anti-Malware Protection. This is one of the core security measures of Windows 10 on a UEFI-equipped machine. Unless you’re a security researcher or a driver developer, we can’t think of any reason to disable this important security check.
• Disable Automatic Restart After Failure. Use this option if you’re getting Stop errors (blue-screen crashes) and you want the opportunity to see the crash details on the Stop error screen instead of simply pausing there before restarting.

The second page of the Advanced Boot Options menu includes a single menu choice that starts the Windows Recovery Environment. (We discuss this and other recovery tools in more detail in Chapter 16.)