CompTIA A+ Certification All-in-One For Dummies, 5th Edition
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This Cheat Sheet gives you quick facts to remember on test day to help you answer questions found on the A+ Certification exams. Before the A+ exams, you’ll want to review some of the major Windows concepts, including boot files, recovery tools, RAID types, and troubleshooting utilities.

Windows recovery tools

One of the hardest tasks to perform when troubleshooting a system is fixing a system that will not boot. The A+ Certification exams expect you to be comfortable with the different recovery tools available in Windows. This table reviews popular recovery tools and specifies where you can find the recovery tool — be sure to know these for the A+ Exam.

Utility Description Access
Recovery Console Command line interface for troubleshooting disk issues and boot problems Boot off the Windows installation CD or using the boot menu if preinstalled
Repair Mode Provides access to GUI and command line recovery tools Boot off the Windows installation media or recovery media.
Restore points A snap-shot of a system’s configuration; used to revert to a system’s state before a driver or software was installed From the Start menu, select All Programs→Accessories→System Tools→System Restore. Select Restore My Computer to an Earlier Time and click Next. Choose your desired restore point and click Next, and then click Next again. Windows will now boot to that restore point.

Windows allows you to boot your operating system to a restore point which allows you to revert back to that system configuration — very useful if your system has been hit with a virus. In order to boot to a restore point, you boot off the Windows installation media and choose Repair Your Computer, then System Restore from the System Recovery dialog box.

You can also get to restore points through Safe Mode, which could prove useful if you have been hit with a virus and are unable to launch System Restore normally.

Safe Mode Loads the operating system with minimal drivers An advanced startup menu option (F8)
Last Known Good Configuration Loads the configuration from the last time you successfully booted and logged on An advanced startup menu option (F8)
Automatic System Recovery (ASR) An automated installation and restore of Windows Press F2 during bootup

RAID types

You will need to know types of RAID for the A+ Certification Exam. RAID (Redundant Array of Inexpensive Disks) is a method of implementing redundancy (duplicated information) on your hard drives — if one disk fails, the other disk(s) can provide the missing information. There are many different levels of RAID, but the following are the only RAID levels pertinent to the A+ Exam:

  • RAID 0: Disk striping (striped volume). With RAID level 0, the data is split across drives with no data redundancy. RAID level 0 improves read and write performance by writing to multiple drives at the same time. You need a minimum of two drives.

  • RAID 1: Disk mirroring/duplexing (mirrored volume). With disk mirroring, the data is written to both drives involved in the mirror in order to provide data redundancy. Windows 7 supports disk mirroring.

  • RAID 5: Disk striping with parity (RAID 5 volume). With RAID 5 volumes, the data is written to multiple drives along with parity information that is used to help recover data if a single drive fails. RAID 5 volumes need a minimum of three disks.

  • RAID 10: Mirrored disk striping. RAID level 10 is also known as RAID 1+0 because it is a disk striping while mirroring the data written in the stripe.

Bus architectures

Another term for the expansion slots on a computer’s motherboard is bus slots. A number of different bus architectures have been developed over time. For the A+ Exam, you need to be able to identify the differences between each of these bus architectures and know which ones are more popular today.

Architecture Bus Width (In Bits) Speed
PCI 32/64 33 MHz
AGP 32 66 MHz (1x), 133 MHz (2x), 266 MHz (4x), 533 MHz (8x)
PCMCIA (laptops) 16 33 MHz
PCI-X 32/64 66/133/266/533 MHz
PCIe Serial Uses multiple lanes with each lane carrying 250 MBps. As an example, a PCIe x1 slot can carry data at 250 MBps, while a PCIe x4 slot can carry data at 1 GBps. PCIe version 2 doubles those transfer rates.
miniPCI 32 33 MHz

USB and FireWire standards

The most popular ports used today on the system are the USB and FireWire ports — which allow you to connect devices such as flash drives, digital cameras, and digital video cameras. This table compares features of USB and FireWire, including the transfer rate and number of devices supported.

Standard Transfer Rate Device Support
USB 1.0 12 Mbps 127 devices
USB 2.0 480 Mbps 127 devices
USB 3.0 5 Gbps 127 devices
USB 3.1 10 Gbps 127 devices
IEEE 1394 400 Mbps; also known as FireWire 63 devices
IEEE 1394b 800 Mbps; also known as FireWire 800 63 devices
FireWire S1600 1.6 Gbps 63 devices
FireWire S3200 3.2 Gbps 63 devices

CompTIA troubleshooting process

CompTIA publishes a six-step process related to the troubleshooting process. You will need to understand what they are on your A+ Exam. The six steps are:

  1. Identify the problem.
  2. Establish a theory of probable cause.
  3. Test the theory to determine cause.
  4. Establish a plan of action to resolve the problem and implement the solution.
  5. Verify full system functionality and if applicable implement preventative measures.
  6. Document findings, actions, and outcomes.

Windows boot files

Windows utilizes four boot files, and you will need an understanding of all four of them for the A+ Exam. The four boot files for Windows are:

  • bootmgr: Operating system loader code; similar to ntldr in previous versions of Windows.
  • Boot Configuration Database (BCD): Builds the operating system selection menu and data resides in the BCD store. You can edit the boot configuration data with the bcdedit utility.
  • exe: Loads the Windows operating system if selected from the operating system selection menu provided by BCD.
  • exe: Resumes the Windows operating system if the system is started from a hibernate state.

Power-on self-test (POST) error code categories

Each hardware manufacturer has its own diagnostic codes that identify specific POST errors. You need to consult the manufacturer documentation for the diagnostic codes for your hardware, but the general breakdown of the code categories is as follows:

  • 100–199: Motherboard error
  • 200–299: Memory error
  • 300–399: Keyboard error
  • 600–699: Floppy drive error
  • 1400–1499: Printer error
  • 1700–1799: Hard drive error

Windows troubleshooting utilities

As an A+ Certified Professional you will troubleshoot a number of different problems on the system — this table outlines some of the popular utilities you will use to support or troubleshoot a system. Be sure to know these before taking the A+ Exam!

Filename Name Description
chkdsk.exe Check Disk Check your hard drive for problems with the file system and for bad sectors.
regedit.exe Registry Editor Make changes to Registry values; can be used to make selective backups. Prior to Windows XP, there were two editors: regedit.exe and regedt32.exe.
defrag.exe Disk Defragmenter Used from the command line, or graphically through the Microsoft Management Console (MMC) and dfrg.msc.
sfc.exe System File Checker Verifies that system files have not been modified; or, if they have, replaces them with the original. It works with the hidden C:\windows\system32\dllcache directory and the original operating system CD.
taskmgr.exe Task Manager See running programs and services, terminate problems, and view rudimentary performance information about the system.
perfmon.exe Performance Console View detailed performance information
msconfig.exe System Configuration Tool Reconfigure the boot process for troubleshooting and diagnosing the boot process.
msinfo32.exe System Information View hardware and configuration information for your computer.
tasklist.exe Task List Display a list of running applications or services on a computer.
taskkill.exe Task Kill Terminate a running application or service on a computer.
gpupdate.exe Group Policy Update Re-process Active Directory (AD) Group Policy Objects (GPO) on the computer.
gpresult.exe Group Policy Results Evaluate the resultant policy results and list all GPOs which apply to the current computer or user.
eventvwr.msc Event Viewer Logging component of the operating system; the central location for all logging activity.

About This Article

This article is from the book:

About the book authors:

Glen E. Clarke, A+, Network+, Security+, is an independent trainer and consultant. Edward Tetz, A+, MCSE, MCT, has written several guides to MCSE and other certifications. Timothy L. Warner, MCSE, MCT, A+, is an IT professional, technical trainer, and author.

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