Different Boot Options in Windows

Spread the love

Before you start

Objectives: Learn which different boot mode options are available and when should we use them.

Prerequisites: no prerequisites.

Key terms: mode, boot, safe, start, configuration, enable, option, driver, services, problem, vga


Boot Modes

If we have problems starting our system, or if it will start but it’s having some troubles, we might be able to restart the system in an alternative mode. Alternative boot modes allow us to customize which services are loaded during the boot. By eliminating unnecessary services we might be able to get the system up and running so that we can fix the problem that we’re having.

To select a different Windows boot mode we have two different options. The first option is to press F8 during boot up. When the system starts we see a black BIOS screen with a summary of our computer configuration (amount of memory, installed hard drives, assigned IRQs, etc). If we press F8 at that point we will be presented with a Boot Mode menu where we can select which start up mode we want to use. Alternatively if we’re in Windows we can use the MSconfig.exe utility to specify which start up mode we want to use. Note that we cannot choose every boot option from Msconfig.

In Advanced Boot Menu we have several different options to choose. Options can be:

  • Safe Mode
  • Safe Mode with Networking
  • Safe Mode with Command Prompt
  • Enable Boot Logging
  • Enable VGA Mode (in Windows XP), or Enable low-resolution video (640-480) (in Windows 7)
  • Last Know Good Configuration
  • Recovery Console
  • Directory Services Restore Mode (used on a Windows Domain Controller to perform a directory service repair)
  • Debugging Mode
  • Disable Automatic Restart on System Failure
  • Disable Driver Signature Enforcement (Windows 7)

Safe Mode

Probably the most widely used alternative boot mode is Safe Mode. When we start the system in Safe Mode we start the system using a basic set of system files and drivers. It loads only the generic mouse, monitor, keyboard, storage device, base video driver which starts in 16 color VGA (640 by 480), Event Log service and some other services that are absolutely necessary. In Safe Mode we don’t have networking abilities. This can help us determine if the problem is driver related or software related.

We can use Safe Mode if we have a system that is having trouble booting into Windows. More than likely it will boot into Safe Mode. Sometimes the cause of the problem is a bad device driver or some service that’s causing problems for Windows. When we start in Safe Mode, we eliminate all extra device drivers and services. We only load a basic set of drivers and basic set of services. When we boot our system using Sage Mode, we can then use Device Manager and other system tools to try and repair our system. For example, we can use Device Manager to roll back drivers or disable devices that might be causing the problem, we can use Add or Remove Programs to uninstall software. Also, we can disable services or applications that load at startup or we can use System Restore to restore the system to a known good restore point. We should start by undoing the most recent change to our system. It that doesn’t fix the problem we can disable all unnecessary devices and services and try to boot our computer. If we are successful, we should then enable each device and service one by one in order to determine what is causing the problems.

Safe Mode with Networking

Safe Mode with Networking is almost the same as the standard Safe Mode. It loads exactly the same drivers and services as the standard Safe Mode, but it also starts up networking (loads network drivers). This can be useful if we need to download a new driver, application update, etc. With standard Safe Mode we can’t do that because we don’t have any networking capabilities. If we do need to get on the network then we can use Safe Mode with Networking. On the other hand this option may not work if the source of the problem is a network component. That’s because this mode may load the component that is causing the problem.

Safe Mode with Command Prompt

This mode starts up the system in a similar manner as standard Safe Mode, however instead of displaying the standard Windows graphical interface we see a command prompt window. Actually, it simply doesn’t load the Windows Explorer process. Using the command prompt window we can do various things. Well, the thing is that it does load a graphical user interface but it just displays a command window in the graphical user interface instead of our usual start buttons and desktop icons.

Enable Boot Logging

Enable Boot Logging option records all the drivers and all the services that were either loaded or not loaded in the startup. All that information is saved to a file called NTBTLog.txt, which is saved in Windows directory (in Windows 2000 or Windows NT it’s in c:WinNT). This boot log can be useful in determining the cause of system start up problems. In that file we will see the last driver which loaded and after which the error occurred. Enable Boot Logging turns on logging when the computer is started with any of the Safe Boot options except Last Known Good Configuration.

Enable VGA Mode (Low Resolution Video)

Although Safe Mode actually loads in VGA, Enable VGA Mode is different than Safe Mode. Enable VGA Mode option loads everything except for a third-party display driver that may be preventing Windows from starting correctly. It loads a basic VGA display driver. Enable VGA Mode is useful when troubleshooting new video driver or a new video card that is causing Windows to not start up properly. In Windows 7 this option is called Enable low-resolution video (640-480).

Last Known Good Configuration Option

The Last Known Good Configuration starts the system using the registry and the set of drivers that Windows last used successfully (configuration that worked). Each time a user successfully logs on to Windows, the registry configuration is saved as the Last Known Good configuration. In this case any changes that we’ve made since the last successful start up will be lost. Note that we should only use the Last Known Good Configuration in case of incorrect configuration. This will only help us if we have a configuration problem with an existing driver or with an existing file. If we have a problem caused by a corrupted driver file or something like that, this option will not help us. Also, If we have recently made a change to a system that caused it to fail, but have not successfully logged on since making the change, we can use the Last Known Good configuration option to restore the registry to the last working configuration. However, if we have logged on successfully since the damaging change was made, the Last Known Good configuration will not help us.

Debugging Mode

Debugging Mode option turns on kernel mode debugging in Windows. Debugging information can be sent across a serial cable to another computer that is running a debugger, by default configured to use COM2. This mode is intended for IT professionals and system administrators.

Disable Automatic Restart on System Failure

This mode will prevent Windows from automatically restarting if an error causes Windows to fail. By default, Windows is configured to reboot whenever a critical system error occurs (Blue Screen of Death). When the error occurs, we only have a short period of time before the system reboots. This might not be sufficient to read and record the error information. Also, we can use this option to stop the loop where Windows fails, attempts to restart, and fails again repeatedly.

Disable Driver Signature Enforcement

This option will allow us to install unsigned drivers, and ignore the driver signing settings in Windows.

Directory Service Restore

Directory service restore mode option is not related to Windows client computer. It is used on domain controllers to start the server without loading the Active Directory service. It is used to restore or fix the Active Directory database or related issues.

Remember

The purpose of boot modes is to provide us with an alternative way to boot the system so that we can go in and fix the problem, and then restart in regular mode. To select a different Windows boot mode we can press F8 during boot up, or we can us MSConfig.exe utility. In Safe Mode we start the system using a basic set of system files and drivers.