Chapter 19

Troubleshooting Theory, OSs, and Security

The following CompTIA A+ 220-802 Exam objectives are covered in this chapter:

• 4.1 Given a scenario, explain the troubleshooting theory.
  • Identify the problem: Question the user and identify user changes to computer and perform backups before making changes
  • Establish a theory of probable cause (question the obvious)
  • Test the theory to determine cause: Once theory is confirmed determine next steps to resolve problem; If theory is not confirmed re-establish new theory or escalate
  • Establish a plan of action to resolve the problem and implement the solution
  • Verify full system functionality and if applicable implement preventive measures
  • Document findings, actions, and outcomes
• 4.6 Given a scenario, troubleshoot operating system problems with appropriate tools.
  • Common symptoms: BSOD, Failure to boot, Improper shutdown, Spontaneous shutdown/restart , RAID not detected during installation, Device fails to start, Missing dll message, Services fails to start, Compatibility error, Slow system performance, Boots to safe mode, File fails to open, Missing NTLDR, Missing Boot.ini, Missing operating system, Missing Graphical Interface, Graphical Interface fails to load, Invalid boot disk
  • Tools: Fixboot, Recovery console, Fixmbr, Sfc, Repair disks, Pre-installation environments, MSCONFIG, DEFRAG, REGSVR32, REGEDIT, Event viewer, Safe mode, Command prompt, Emergency repair disk, Automated system recovery
• 4.7 Given a scenario, troubleshoot common security issues with appropriate tools and best practices.
  • Common symptoms: Pop-ups, Browser redirection, Security alerts, Slow performance, Internet connectivity issues, PC locks up, Windows update failures, Rogue antivirus, Spam, Renamed system files, Files disappearing, File permission changes, Hijacked email, Access denied
  • Tools: Anti-virus software, Anti-malware software, Anti-spyware software, Recovery console, System restore, Pre-installation environments, Event viewer
  • Best practices for malware removal
  • Identify malware symptoms
  • Quarantine infected system
  • Disable system restore
  • Remediate infected systems
  • Update anti-virus software
  • Scan and removal techniques (safe mode, pre-installation environment)
  • Schedule scans and updates
  • Enable system restore and create restore point
  • Educate end user

Mentioning the words troubleshooting theory to many technicians can cause their eyes to roll back in their heads. It doesn’t sound glamorous or sexy, and a lot of techs believe the only way to solve a problem is to just dive right in and start working on it. Theories are for academics. In a way they’re right; you do need to dive in to solve problems because they don’t just solve themselves. But to be successful at troubleshooting, you must take a systematic approach.

You may hear people say, “Troubleshooting is as much of an art as it is a science,” and our personal favorite, “You just need to get more experience to be good at it.” While there is an art to fixing problems, you can’t ignore science. And if you need experience to be any good, why are some less experienced folks incredibly good at solving problems while their more seasoned counterparts seem to take forever to fix anything? More experience is good, but it’s not a prerequisite to being a good troubleshooter. It’s all about a systematic approach.

Applying a systematic approach to troubleshooting is key; systematic solutions also work well in preventing problems in the first place. Many of the computer problems you stress over can be prevented.

Preventive maintenance tends to get neglected at many companies because technicians are too busy fixing problems. Spending some time on keeping those problems from occurring in the first place is a good investment of resources.

In this chapter, we’ll look at the two systematic methods we just talked about. First, we’ll cover troubleshooting theory and the steps you need to take to successfully solve problems. Then, we’ll look at some ways to help keep your systems running in top shape.