Operating System Troubleshooting Tools – CompTIA A+ 220-902 – 4.1

If you’re going to troubleshoot an operating system, then you’re going to need the right tools. In this video, you’ll learn how to use BIOS diagnostics, SFC, system repair disks, and more.

<< Previous: Operating System TroubleshootingNext: Troubleshooting Common Security Issues >>


You may find some of the most convenient troubleshooting tools to be built into the BIOS of your computer. Many modern BIOS implementations include diagnostics as part of the basic input/output system. So by simply starting the BIOS, you’re able to get feedback on temperature, CPU usage, memory, voltage information. You might also find a set of specialized hardware tests in the BIOS as well that will check all of the different components of your motherboard. Some of the newer UEFI BIOS can even access network settings and USB drives to load additional software as well.

If you’re concerned that the operating system files of your computer may be damaged, or there’s a problem, you should run SFC. This is the system file checker, and it performs an integrity scan of your operating system files. This will take a bit of time as it goes through all of your operating system files, but if it finds a problem with any file it will correct that file and allow you to restart your system with the newer corrected files.

The Windows operating system includes a number of logs that you can access. Most of them will commonly be available in the event viewer for applications, security operating systems, and other logs as well. You can also have your system log during the boot process. Simply go to System Configuration and choose the option to boot logs, so that when you restart your system a file will be created in the Windows directory called ntbtlog.txt, and you can get more details about what’s happening during the boot process.

In Linux, individual applications can write their log files wherever they’d like. But a very common place to find most of the logs in Linux is /var/log. And in Mac OS X, you can easily access the logs under Utilities in the Console.app. And you’ll be able to see all of the different log information that happens to be in your console.

If you’re having problems with your operating system that you can’t fix while the OS is running, you may need to start your Windows command prompt, and access the operating system before the OS starts. You can do this in Windows 7 from System Recovery Options and choose Command Prompts. In Windows 8 and 8.1, you would choose Other Options, choose Troubleshoot, choose the Advanced Options, and finally choose Command Prompt.

This Windows command prompt gives you access to the operating system. You can modify services. You can repair or replace files. So it’s very powerful– and of course very dangerous. You need to know exactly what you’re doing when you’re using the Windows command prompt.

But when you need this kind of power, it’s nice to be able to use, copy, rename, or replace operating system files. You can modify what services might be starting during the Windows Start Up. You can fix boot sector problems, or master boot record issues. And you can even partition and format different parts of a drive.

If you were to press F8 during the start-up of Windows 8 or Windows 8.1, you’d get an option screen. If you choose Other Options, and then from there choose the troubleshoot, you have a number of different options available.

Under Advanced Options is the one you would use to choose the command prompt that would then give you access to the Windows command prompt. It’ll prepare the command prompt on the screen, ask you to input an account to provide access to the system. You would then provide the password of the account you chose. And finally you would have the command prompt available to use.

If you need additional tools to be available during the startup process, you may want to use a system repair disk. This is something that will boot the computer and provide you with a number of recovery options. And it’s available in Windows Vista, Windows 7, and Windows 8 and 8.1.

Your computer may not come with installation media, which is a common problem. So it’s very important that you create one of these system repair disks. Under the Windows Backup and Restore, there’s an option to create a system repair disk. One important consideration when using the system repair disk is that it does not modify or format any part of your system unless you tell it to. You have full and complete control when you’re running the system recovery options from the system repair disk.

Whenever you start the system repair disk, you’re in this Windows pre-installation environment– or Windows PE. This is a Windows operating environment that just has the minimal features available. But it’s very useful if you’re trying to troubleshoot or install an operating system.

You can of course build your own Windows PE. In Windows Vista and Windows 7, you would use the Automated Installation Kit, or WAIK; and for Windows 8 you would use the Assessment and Deployment Kit. You might also check on the internet for other options for Windows PE. There are a number of third-party options out there that are quite good, and you can use those as your troubleshooting boot disk.

One tool I use all the time in Windows is Microsoft System Configuration, or msconfig. This has a number of different options for booting the system. I can enable and disable what programs are starting during the boot process. I can enable and disable services. And I can modify exactly what happens during the startup process all by using msconfig.

A defragmentation tool is also built into Windows. This is especially helpful if you’re running a spinning hard drive where different parts of the file may be located in different parts of the drive. And the defragmentation process takes all of those different pieces and puts them into a single contiguous area on the drive. This will improve the read and the write time of that file, thereby improving the overall performance of your operating system.

You can find a graphical version of the defragmentation utility in the drive properties. You’ll find the defragmentation option, and you can click Defragment Now to start it. Or you can go to the command line and simply type defrag. This defragmentation may already be part of your weekly schedule on your system. You can either check or add it to your schedule in the Control Panel under Administrative Tools, and choose Task Scheduler.

The Windows registry contains all of the important details of your operating system– information about the kernel, driver configurations, the services, the application settings. Everything that is critical to your system is saved in this registry. You normally don’t have to change anything in the registry unless there’s a problem.

So if you are troubleshooting, you may want to run REGEDIT. This is the registry editor where you can modify specific registry entries. You can add keys. You can modify different options, and you can import and export parts of the registry as well.

If you need to register a DLL in Windows, then you need to use a similar-sounding utility called REGSVR32. This is the Microsoft Register Server, and it allows you to register and unregister DLLs from the operating system. And it of course also updates the registry to use those new DLLs.

The Windows Event Viewer is where you can go to find out everything that’s happening with your operating system. You’ll be able to view details about the applications running on your system, security information about your operating system, what’s happening when you set up an application, and overall events that are occurring with the system.

You’ll also see a number of severities associated with these events. They might be informational. They might be warning messages. Or they may be more extreme situations where there is an error or a critical problem that you need to address. And it will be labeled within the event viewer.

You can access a number of great troubleshooting tools before the operating system even loads. Press F8 before the OS loads, and you’ll be able to reach the advanced boot options. These are the options for Windows 7. The Windows 8 user interface looks a little bit different, although the functions are very similar.

You have to be fast and make sure you press F8 before the Windows splash screen begins to load. If you ever need to run in Safe Mode, you need to run in VGA mode, maybe you need to access the Windows Recovery Console. You do all of that from these advanced boot options by pressing F8.

If you’re having problems getting the Windows operating system to run, you may want to try running it in Safe Mode. You would access Safe Mode by pressing this F8 and getting to the advanced boot options, and then choosing Safe Mode. This is going to load a version of Windows that only runs the drivers necessary to get the operating system running, and this might get you around any problems during the boot process.

There’s also a safe mode with networking that also includes drivers for the network, so that you can access the network once you’ve booted up. And there’s also a safe mode with command prompt, that gives you no Windows Explorer graphical interface. It simply drops you to the command line, and you can then perform any troubleshooting from there.

There’s also an option to start Windows in low-resolution, or VGA mode. If you’re having problems with a video device driver, or with your monitor or display, you might want to try starting in VGA mode. This is a very low-resolution mode, instead of the higher resolution that normally loads with Windows.

You may sometimes hear people tell you that the best way to fix a particular Windows problem is to reinstall the entire operating system and all of your applications. But of course, it’s very time-consuming. Even if it solves the problem it may take a very extended period of time to finally get the problem resolved. Windows 8 and 8.1, though, includes some middle-ground options that don’t include an entire rebuild of the operating system, but can still clean out a number of problems that might occur. They call this function a refresh, which cleans out Windows without actually removing the operating system or any of your important files.

You could also perform a reset as well, which takes the operating system back to factory defaults. You would, of course, lose all of your files and applications. But you don’t have to perform a complete reinstall to get back to that point.

To run a refresh or a reset in Windows 8 or 8.1, you press F8 during the Windows Start Up. You would choose other options. You would then, from the next screen, choose to troubleshoot, and from the troubleshoot screen you can refresh PC, which tells you if your PC isn’t running well, you can refresh it without losing your files; or you can reset your PC, where it will remove all of your files and reset the PC back to the operating system defaults.