How to Run a Diagnostic on a Computer

The Microsoft Windows 8.1 operating system is equipped with several specialized tools designed to diagnose various problems and suggest solutions in the day-to-day functioning of your PC. These include scanning your hard disk for errors, diagnosing and fixing layout problems, and debugging and eliminating DLL (dynamic-link library) load failures. In Windows 8, all maintenance tasks are designed to run automatically in the background with very little user input. However, it is possible to run most of these tools manually.

stethoscope and Laptop
Run diagnostics to find and fix problems.
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One of the most basic Windows diagnostic programs is CHKDSK. This program allows you to scan any of your hard disks (including external drives and thumb drives) for software errors, corrupted files and hardware damage. To run CHKDSK in the classic mode in Windows 8.1, press "Windows-E," highlight a drive to select it and right-click to open the dialog box. Highlight “Properties,” select the “Tools” tab and select the “Check Now” tab on the error checking box. Depending on your Win 8.1 permissions, you may be asked to contact the network administrator or to log in as an administrator to perform this task.


In the automatic maintenance mode, Windows 8.1 runs background system scans constantly, looking for virus and malware intrusions using your installed virus checking software. To run your own scan, open “Computer,” right-click on the drive you wish to scan and select “Scan” from the drop-down menu. Virus and malware scans generally come with two choices: quick and thorough. A quick scan can usually detect and delete most malware. A thorough scan takes much longer and should be run overnight or during a period of several hours when your machine is not in use.

Optimize Drives

Win 8.1 uses drive optimization to increase the efficiency of both traditional hard drives and newer solid state drives. Open a Search box by swiping or moving the mouse from the right upper screen towards the center. Type "Defrag” and select “Defragment and Optimize Your Drives.” Click “Status,” ”Analyze” and “Optimize” if the drive is more than 10 percent fragmented.

Third Party Diagnostic Tools

Third-party diagnostic tools include SiSoftware Sandra 2014, which packs a load of analysis, benchmarking and diagnostic utilities for PCs, and PCMark8 from FutureMark, which merges battery life, PC performance and tests for several Microsoft Office apps. Both include detailed instructions as to how to deploy their various tests and both suggest possible causes of, as well as solutions to, any detected performance problems.