Diagnosing Computer Problems: 10 Steps (with Pictures)

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Diagnosing Computer Problems: 10 Steps (with Pictures)
Diagnosing Computer Problems: 10 Steps (with Pictures)

Many people face everyday computer problems that are easy to solve, yet they are unable to diagnose the real problem. While there are many possible problems with a computer, this article explains what to look for when dealing with common problems.


Diagnose a Computer Problem Step 1

Step 1. Check the POST information

POST stands for Power On Self Test. This is usually the first or second to appear on a computer after turning on the machine. This is displayed before the operating system starts loading. The POST will show any hardware issues (which prevent the computer from booting), as well as hardware issues that cause the computer to start but not run at full capacity.

Diagnose a Computer Problem Step 2

Step 2. Note the loading time of the OS (operating system)

More than usual loading time can indicate hard drive search errors (or other errors).

Diagnose a Computer Problem Step 3

Step 3. Watch for graphical issues once the OS loads

Decreased graphics can indicate driver issues or hardware errors with graphics cards.

Diagnose a Computer Problem Step 4

Step 4. Take an auditory test

An auditory test is an unorthodox, but still effective way of assessing how well a computer is working. Play an audio file of reasonable length (usually above 30 seconds). If the audio stutters or sounds sluggish, it usually means that the processor has to pull hard, or there isn't enough RAM to run all of the loaded programs. Changing the startup sound is a great way to apply this test. Another issue related to choppy sound has to do with PIO (Programmed Input/Output) mode. This affects how the hard drive reads and writes data from a drive. Switching to DMA makes for faster reads and writes, and can sometimes fix choppy audio.

Diagnose a Computer Problem Step 5

Step 5. Check all recently installed hardware

Many operating systems, especially Windows, can conflict with new drivers. The driver may be badly written, or it may conflict with another process. Windows will usually notify you about devices causing or having a problem. Check this through Device Manager, which can be accessed from Control Panel > System > Hardware tab, then by clicking Device Manager. Use this to check and control the properties of the hardware.

Diagnose a Computer Problem Step 6

Step 6. Check recently installed software

Software may have higher system requirements than the machine can handle. Chances are, if a problem starts after launching some software, that software is the cause. If the problem occurs right at startup, then it could be caused by software that starts automatically at startup.

Diagnose a Computer Problem Step 7

Step 7. Check RAM and CPU usage

A common problem is a jerky or slow system. If a system is jerky, it's a good idea to consider whether a program needs more resources than the computer can supply. An easy way to check this is through the Task Manager. Right-click on the taskbar, select Task Manager and click the Processes tab. The CPU column contains a number that indicates the percentage of CPU that the process is using. The Memory column indicates how much memory a process is using.

Diagnose a Computer Problem Step 8

Step 8. Listen to the computer

If the hard drive produces scratchy or loud noises, turn off the computer and have a professional diagnose the hard drive. Listen to the CPU fan. This will run at a high speed when the CPU is running above its own power.

Diagnose a Computer Problem Step 9

Step 9. Run a virus and malware scan

Performance issues can also be caused by malware on the computer. A virus scan can clarify any problems. Use a frequently updated virus scanner (such as Norton or Avast!) and a frequently updated malware scanner (such as Spybot Search & Destroy).

Diagnose a Computer Problem Step 10

Step 10. Check if there are any problems in safe mode

As a last resort, check the issue in safe mode. To enter safe mode, repeatedly press F8 during the POST phase (this works on most systems). If the problem persists in safe mode, then chances are the operating system itself is the culprit.


  • These procedures can help identify common problems, but searching for a specific problem may require special tools or techniques.
  • If you're unsure about diagnosing or repairing a computer problem, it's best to let a certified technician do it for a reasonable fee.


  • Do not try to fix problems if you are not sure what you are doing and what the result will be, as well as what the possible consequences may be.
  • Always consult a competent computer technician, whether solving problems yourself or under supervision.

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