CompTIA A+: Software Troubleshooting Concepts
Importance ★★★★☆ · 23% (estimate)
Overview
This chapter is about fixing problems with Windows, apps, and mobile software, and spotting signs of malware. Questions describe a symptom, such as a slow PC or a crashing app, and ask what to check or which tool to use first.
For Windows problems, start with the least disruptive fix. Restart the computer or the app, check for updates, and look in Event Viewer for errors. Safe Mode starts Windows with only basic drivers and services, which helps show whether a driver or startup program is the cause. System Restore rolls system files and settings back to an earlier point without touching personal files. If one user's settings are damaged, rebuilding the user profile can help.
Malware often shows itself through browser redirects, pop-ups, a changed home page, missing files, strange accounts, or a security app that has been turned off. Certificate warnings on many trusted sites can mean the computer's date and time are wrong. On phones, apps that crash or drain the battery can often be fixed by updating, clearing the app's cache, or reinstalling the app.
Key concepts
Safe Mode
A startup mode that loads only basic drivers and services. If the problem disappears there, a driver or startup item is likely the cause.
Memory tipTest without extras = Safe Mode.
System Restore
Rolls Windows system files, drivers, and settings back to a saved restore point. It does not delete personal documents.
Memory tipBad driver install yesterday = restore to before it.
Blue screen (BSOD)
A stop error when Windows hits a serious problem, often caused by a bad driver, failing hardware, or damaged system files.
Memory tipNote the stop code and check recent driver changes.
Browser redirect
Searches or pages are sent to sites the user did not choose, a common sign of adware or other malware.
Memory tipUnexpected sites plus pop-ups = scan for malware.
Rebuild profile
Create a fresh user profile when one user's settings are corrupted while other users work fine.
Memory tipOnly one user has the problem = suspect the profile.
Often tested
- A slow PC: check Task Manager for programs using high CPU, memory, or disk.
- Certificate errors on many sites: check the system date and time first.
- If an update causes problems, you can uninstall that update or roll back the driver.
- On mobile devices, force-stop and update a crashing app before resetting the whole device.
3 sample questions
Verified practice questions from this unit.
Question 1. A technician suspects that a driver or startup program is causing Windows problems. Which startup option loads Windows with only basic drivers and services?
- ① UEFI/BIOS setup
- ② Airplane mode
- ③ Safe Mode
- ④ Fast startup
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Answer: ③ Safe Mode
Key point: Safe Mode = Windows with minimal drivers
Safe Mode starts Windows with only the basic drivers and services it needs. If the problem goes away in Safe Mode, a driver or startup program is the likely cause, and the technician can remove or update it from there.
Wrong choices
- UEFI/BIOS setup: UEFI/BIOS setup changes firmware settings. It does not start Windows with fewer drivers.
- Airplane mode: Airplane mode only turns off wireless radios.
- Fast startup: Fast startup speeds up booting. It does not limit which drivers load.
Question 2. A user's web browser keeps opening pop-up ads, and searches are sent to websites the user did not choose. What is the most likely cause?
- ① Too little RAM
- ② A failing network card
- ③ Malware, such as adware or a browser hijacker
- ④ A full printer queue
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Answer: ③ Malware, such as adware or a browser hijacker
Key point: Redirects and pop-ups = likely malware
Unwanted pop-ups and searches that go to strange sites are classic signs of adware or a browser hijacker. The technician should scan with updated anti-malware tools and check the browser for unknown extensions and changed settings.
Wrong choices
- Too little RAM: Low memory makes the PC slow, not redirect searches.
- A failing network card: A bad network card causes lost or slow connections, not pop-ups and redirected searches.
- A full printer queue: A printer queue has nothing to do with browser behavior.
Question 3. A user says their Windows PC has become very slow. Which tool should the technician open first to see which programs are using the most CPU and memory?
- ① Disk Management
- ② Task Manager
- ③ Device Manager
- ④ Event Viewer
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Answer: ② Task Manager
Key point: Task Manager shows live CPU, memory, and disk use
Task Manager shows running programs and how much CPU, memory, disk, and network each one uses right now. Sorting by a column quickly shows which program is slowing the PC down.
Wrong choices
- Disk Management: Disk Management manages drives and partitions, not running programs.
- Device Manager: Device Manager shows hardware and drivers, not which programs are using resources.
- Event Viewer: Event Viewer shows logs of errors and events, not live CPU and memory use.
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