Troubleshooting Microsoft Windows OS | CompTIA A+ 220-1002 | 3.1

In this video you will learn about some common symptoms & solutions for Microsoft Windows operating system problems.

Slow System Performance

Plenty of issues can cause slow performance in Windows. Below are some possible reasons along with solutions:

Windows System Performance Troubleshooting
Linux Performance Optimization
macOS Performance Optimization

Limited Connectivity/Local Connectivity

In Windows 7 if you see a yellow ! symbol or in Windows 10 you see a red X icon next to the network icon in the taskbar, that indicates that there is limited connectivity to the network (meaning the Internet can’t be reached…also known as local connectivity). If you see these symbols, the first thing you want to do is to check for connectivity on other devices. If the other devices cannot connect, do the following:

  • In Windows 7, open the Network & Sharing Center and then click the red X in the Internet connection dialog. This will launch the Internet troubleshooter, then proceed to follow the recommendations.
  • In Windows 8/8.1, click Search to locate & begin the Internet troubleshooter, then follow the recommendations.
  • In Windows 10, click the network icon in the taskbar to open up the Network Status window, then follow the troubleshooting recommendations.
  • If there are connection issues with the OS, turn off the modem, router, or access device for a few minutes, then turn it back on. In most instances, this will resolve the problem. If not, you may have to contact your ISP as this might indicate a bigger issue beyond your LAN.

Failure to Boot

A boot failure is the inability to locate and/or read the operating system from the designated disk. This can be caused by incorrect boot configurations in the BIOS, corrupt or missing boot files, & missing driver files. Different operating systems have different solutions for this type of problem.

Windows Boot Errors

Windows uses the BCD (Boot Configuration Data) file & bootmgr (Windows Boot Manager) during the startup process and if these files are corrupted or missing, the following error messages will be displayed:

  • BOOTMGR is missing:  If the bootmgr is missing or corrupt this message appear.  The black screen may also say Press Ctrl+Alt+Del to Restart; however, doing so may not necessarily fix the issue.
  • The Windows Boot Configuration Data file is missing required information:  This message means that either the bootmgr entry is not present in the BCD store or that the Boot\BCD file on the active partition is damaged or missing.

Two ways to repair a missing bootmgr file:

  • Boot to the System Recovery options and then select Startup Repair.  This should repair the system and require a system reboot.  To access the options in Windows 7, restart the computer and hold the F8 key before the Windows logo appears.  In Windows 8 & 10, locate the Advanced Startup Settings menu.
  • Boot to the System Recovery options and select the Command Prompt option.  Type the bootrec /fixboot command.
Repair Missing Bootmgr

Linux Boot Errors

If Linux won’t start normally:

  • Hold down the Shift key while starting the system. 
  • If the GRUB or GRUB2 boot loader appears, select Rescue or Recovery to load a minimal version of Linux.
  • With some distros you might need to select Advanced before you can select a recovery option.
Grub2 Linux

From the Recovery menu, you might be offered a variety of options to fix your system such as:

  • resume: Continues the normal boot process.
  • clean: Frees up space on your file system; use it if the disk is almost full.
  • dpkg: Repairs broken software; use this if software installation failed.
  • failsafex: Enables system to boot to GUI.
  • fsck: Repairs file system errors.
  • grub: Updates grub boot loader.
  • network: Enables networking, which is turned off in Recovery mode.
  • root: Opens system in read/write root shell mode (for experts only).
  • system-summary: Displays information about the system.

macOS Boot Errors

To launch special startup modes in macOS, press Cmd+R as soon as startup sound plays, continue pressing until you are prompted to select a language, select your language, and the macOS Utilities menu appears.  The following options will appear:

  • Restore from Time Machine Backup:  If a backup exists and you wish to restore it.
  • Reinstall macOS:  Install a new version of macOS.
  • Get Help Online:  Open online help and remote diagnostics options.
  • Disk Utility:  Select this option to repair problems with hard drives.

To boot from a different partition than usual, such as a Boot Camp partition, start up your macOS system and hold down the Alt or Option key until a list of bootable drives appears.  Select the drive to use.

Other Symptoms & Common Solutions

Other common symptoms and solutions related to A+ Core 2 Objectives in section 3.1 included:

Common symptoms, causes, & solutions for a malfunctioning OS