Diagnostic tool in Windows 11: a complete guide to taking care of your PC

Informatec Digital » Resources » Diagnostic tool in Windows 11: a complete guide to taking care of your PC

Having good diagnostic tools in Windows 11 makes all the difference between reacting when your PC is already a mess and getting ahead of problems before something serious happens. Many users only remember these utilities when they experience crashes, blue screens, or strange restarts, but Microsoft's system and several third-party applications offer a great deal for monitoring your computer's health.

At the same time, it's easy to get frustrated: some people update to a new version like Windows 11 24H2 and suddenly problems start: the Start button freezes, search stops working, the Microsoft Store won't open, certain formats like JPEGs won't open… and on top of that, some official tools only generate reports without fixing anything. In this context, it's important to know exactly what each tool does, its limitations, and what real alternatives we have for detecting and, above all, fixing errors.

What do we mean by diagnostic tool in Windows 11?

When we talk about a diagnostic tool for Windows 11, we're not just referring to a program that magically fixes things. In practice, these are utilities that gather detailed information about the hardware, operating system, network, and security, and present it in a more or less clear way so we can pinpoint the source of a problem.

In many cases, these tools focus on monitoring and logging events : CPU temperature, disk errors, memory failures, application crashes, suspicious processes, performance bottlenecks, etc. Some only provide diagnostics and logging; others offer recommendations, and a few can directly repair certain components.

The real value lies in the fact that the more reliable information we have about what's happening inside the PC, the sooner we can make decisions: replacing a failing hard drive, uninstalling a problematic driver, checking the RAM, or strengthening security. Hardware failures, in particular, are often silent until it's too late, so preventative diagnostics are invaluable.

Windows 11 includes several built-in tools, but there are also third-party utilities that greatly expand what we can see and measure. It's advisable to combine both approaches: use what the system already offers and supplement it with specialized software when a more in-depth view is needed.

Complete hardware monitoring: HWiNFO

One of the best ways to check the health of your PC is to install HWiNFO , a popular free tool that provides an enormous level of detail about your hardware. It's ideal when you suspect overheating, unstable voltages, or components that aren't performing as they should.

With HWiNFO you can see everything from the exact CPU and GPU temperatures to fan speeds, power consumption, individual core clocks, motherboard sensor status, and a long list of other advanced parameters. The amount of data might seem overwhelming at first, but once you get used to it, it becomes an indispensable tool.

The beauty of HWiNFO is that it not only displays static data, but also allows you to monitor in real time while you play, export logs, and compare how your system performs before and after hardware changes or Windows updates. If the CPU reaches 95°C or the graphics card temperature spikes, you'll see it clearly and be able to consider options like custom liquid cooling.

This information helps you detect, for example, whether a crash under load is due to overheating , an insufficient power supply, or a fan that's spinning too slowly. Windows 11 itself doesn't display this level of detail, so HWiNFO is a great complement to the native tools.

Performance Monitor: the integrated performance monitor

Within Windows 11, one of the most underrated utilities is Performance Monitor . It's a powerful, integrated tool that allows you to accurately analyze resource usage over time.

To open it, simply press Win + R , type perfmon or Performance Monitor , and select the first option that appears. Initially, you'll see a graph focused on CPU usage, but the tool goes much further: you can add counters for disk usage, memory, network, queue times, page size, power consumption, and many more indicators.

The real value of Performance Monitor lies in its ability to create monitoring sessions that record specific counters over minutes or hours. This allows you to analyze what happens just before a crash or a performance drop: if the disk reaches 100% usage, if the RAM runs out and the system starts paging frantically, or if a particular process hogs all the resources. In serious diagnostic environments, it's a key tool for understanding bottlenecks and anomalous behavior, enabling you to take steps to optimize services and performance without installing anything extra, as it comes pre-installed with Windows 11.

Although the interface isn't the most user-friendly, in serious diagnostic environments it's a key tool for understanding bottlenecks and abnormal behavior without installing anything additional, as it comes pre-installed with Windows 11.

System stability history: Reliability Monitor

Another little-known gem of Windows 11 is the Reliability History , accessible by searching the taskbar for the "View reliability history" option. This integrated tool displays a clear timeline of all system errors and significant events.

Instead of navigating through complicated technical logs, this view summarizes system behavior on a stability scale of 1 to 10 , day by day. Every program crash, hardware error, failed update, or critical issue is marked on a graph, allowing you to see at a glance when problems started.

By clicking on a specific day, you can see details of the errors , which application crashed, which module was involved, or which update might have triggered the problem. If necessary, you can uninstall programs and clean your PC to see if the error disappears. This is ideal for correlating, for example, whether the crashes started after installing a certain driver or a specific Windows 11 patch.

For any diagnostic task where you want to know if your system has worsened after a change, Reliability Monitor is much more convenient and visual than manually checking the Event Viewer, and is often the first place worth checking when something suddenly stops working.

Network and WiFi diagnostics: WiFi Analyzer and SoftPerfect Network Scanner

Connectivity problems are a classic: the connection is slow, the ping spikes for no apparent reason, or the Wi-Fi seems overloaded. For these situations, using a dedicated diagnostic tool can save many hours of trial and error.

A very useful option is WiFi Analyzer , an application designed to visually analyze how your wireless network behaves. It shows which channel your router is using, which channels are most congested by neighbors' networks, and how strong the signal is at different points in your home or office.

With this data, you can decide to change channels or bands (2,4 GHz vs. 5 GHz) to reduce interference. If the analysis reveals that your router is sharing a channel with several nearby networks, you're likely to experience dropouts and speed reductions, and the tool helps you adjust your router settings for improved stability.

On the other hand, SoftPerfect Network Scanner is excellent for examining which devices are connected to your network, both IPv4 and IPv6. Its free version allows you to list up to 10 devices, which is sufficient in many homes to confirm if someone is using your Wi-Fi without permission.

Being able to see all active devices on the network at a glance, along with their IP and MAC addresses, is helpful for both security and diagnostics: if there are more devices than expected, the network may be overloaded; if a particular device is generating excessive traffic, you can also suspect it. If you have occasional problems with device detection, such as when your PC doesn't detect your mobile phone , these types of scanners help pinpoint the problem.

Tools for monitoring disk status: CrystalDiskInfo and WinDirStat

Storage is a critical factor for the stability of Windows 11. A mechanical hard drive with bad sectors or an SSD with too many errors can be responsible for crashes, blue screens, and extreme slowness, even when the rest of the hardware is perfect.

CrystalDiskInfo is a tool designed specifically to monitor the health of hard drives, SSDs, and external drives. It reads SMART data from the drives (internal health information) and displays it in a simple dashboard with indicators such as temperature, number of errors, reallocated sectors, uptime, and more.

If CrystalDiskInfo marks the drive as "Good ," there's usually no immediate cause for concern. However, if warning messages appear or the health is low, it's advisable to back up your data and consider replacing the drive. This tool doesn't repair the disk, but it does alert you before it fails completely and you lose data.

In addition to the above, WinDirStat is excellent for identifying where your disk space is being used and cleaning up drives with little free space. It scans your disks and displays a visual map where each file and folder occupies a block proportional to its size, in a very clear and graphical way. Thanks to this representation, you can locate huge forgotten files , runaway temporary folders, or remnants of old installations that continue to take up gigabytes, and at the same time, clean your PC inside and out to recover space.

RAM memory check: Windows memory diagnostics and proactive analysis

RAM failures are among the most troublesome: they cause random crashes, unexplained restarts, and difficult-to-interpret blue screens. To address them, Windows 11 includes the Windows Memory Diagnostic , which can be accessed by typing its name in the Start menu search box (Win + S) and running the tool.

When you start it, the system suggests restarting and analyzing the memory before loading Windows. During this special boot process, tests are run on the RAM modules to detect errors. If any problems are found, a warning will appear when you return to the desktop, and the issue will also be recorded in the system logs.

In addition to this classic utility, Microsoft is introducing a new proactive memory diagnostic feature in the latest Windows 11 Insider Program builds (for example, build 26220.6982). This feature runs when the system detects an unexpected restart or an abnormal shutdown.

After this type of failure, Windows will display a notification prompting you to perform a quick memory scan . If you accept, the scan is scheduled for the next restart and runs before the operating system finishes booting. The test takes about five minutes on average and, if it detects errors, provides clear information about the type of failure and possible actions to take.

The goal is to bring more transparency to those "mysterious" restarts related to memory corruption, faulty drivers, or problematic hardware. The data from these diagnostics is collected anonymously so Microsoft can identify common error patterns and refine future updates, although not all computers are compatible: for now, ARM64 systems, configurations with certain administrator restrictions, and machines with BitLocker without Secure Boot are excluded. If you're an advanced user, you can combine these reports with useful Windows 11 scripts that automate periodic checks and cleanups.

Sysmon: the advanced system monitor now integrated into Windows 11

Another key component in the diagnostic arsenal is Sysmon (System Monitor), a tool that for a long time had to be downloaded separately from Microsoft Sysinternals and is now natively integrated into the latest versions of Windows 11. However, it comes disabled by default.

Sysmon acts as a device driver and system service, logging advanced events such as process creation, DLL loading, driver installation, network connections, file creation date changes, and more. It can also log process image file hashes, which is very useful for forensic analysis and security.

This information is written to the Windows event logs, allowing administrators and advanced users to track suspicious activity , pinpoint anomalous behavior following malware infection, or diagnose complex problems that are undetectable with simpler tools. It is, essentially, a highly detailed black box of what is happening on the system.

To enable the built-in version of Sysmon in Windows 11, first make sure you don't have an older, manually downloaded version installed; if so, uninstall it. Then, from the Settings app (Win + I), go to System > Optional features > More Windows features and enable Sysmon in the Windows Features window.

Once the feature is enabled, you need to open a Command Prompt or PowerShell window with administrator privileges and run the command `Sysmon -i` , which initializes the service. From that moment on, the monitor will begin logging events continuously, integrating directly into the system without the need for additional third-party software.

When native tools aren't enough: problems after upgrading to Windows 11 24H2

Microsoft's diagnostic tools aren't always enough to fix everyday problems, especially after some major Windows 11 updates . There are cases of users who, after upgrading from 23H2 to 24H2, have seen their PCs, which previously worked flawlessly, become unstable.

Typical situations include the Start button becoming unresponsive , the search bar freezing, apps failing to open, the inability to connect to the Microsoft Store, or even the inability to open basic files such as JPEG photos.

In some cases, Microsoft support recommends updating to the newer version (for example, from 23H2 to 24H2) in the hope that compatibility issues will be resolved. Sometimes this does improve the situation (for example, programs start working again, or the Start button becomes responsive), but other problems persist: search remains broken, the Microsoft Store won't connect, or the integration of certain applications continues to be problematic.

The built-in diagnostic tool that many users encounter in these cases is limited to displaying logs and reports , without offering a magic "fix everything" button. Even temporarily disabling third-party security software, starting in Safe Mode, and trying to get Windows to recommend alternative update paths doesn't always work.

In these circumstances, beyond using Sysmon, Performance Monitor, or the Reliability History, it may be essential to rely on external tools to rule out hardware problems (memory, disk, power) and determine whether the problem stems from a conflicting update, a faulty driver, or a component that is physically failing. It's also advisable to perform an advanced PCIe diagnostic if you detect issues related to cards or internal connectivity.

Diagnosing and manually repairing damaged system files

A common source of errors and unusual behavior in Windows 11 is corrupted system files . While tools like SFC or DISM can repair many of them automatically, there are cases where a specific file cannot be fixed that way and manual intervention is required.

The typical procedure involves first reviewing the log file where Windows records the results of integrity checks to determine which file is corrupted and its exact location. Once identified, good copies of that file are searched for on the system (for example, on another machine or on installation media) so they can be replaced.

The initial step is to take administrative ownership of the corrupted file. From an elevated command prompt, run the command takeown /f <Ruta_Y_Archivo>For example, for the jscript.dll file located in System32, you would use takeown /f C:\windows\system32\jscript.dll.

Next, the administrators must be given the opportunity to be granted this power. full control over the file. This is done with the command icacls <Ruta_Y_Archivo> /grant administrators:F. Following the previous example, it would be icacls C:\windows\system32\jscript.dll /grant administrators:FThis ensures we have the necessary permissions to replace it.

Finally, the correct version of the file is manually copied over the damaged version, using the command copy <Archivo_Origen> <Archivo_Destino>. For example: uterine copy E:\temp\jscript.dll C:\windows\system32\jscript.dllThe source must be a known valid copy, from a healthy system or reliable sources.

If this process fails to resolve the problem, the damage may affect more internal components or the Windows 11 installation itself, in which case you may need to resort to Windows recovery options : resetting the PC, repairing by booting from installation media, or ultimately reinstalling the operating system from scratch after making a backup.

Security and malware: Malwarebytes, ClamWin and ESET SysInspector

On many PCs, performance issues or strange behavior are not due to updates or hardware, but to malware or unwanted software . Therefore, the concept of a "diagnostic tool" also includes security-focused applications that scan the system for threats.

Malwarebytes is one of the best-known solutions in this field. Although Windows 11 includes Windows Defender, many people supplement its protection with Malwarebytes, either the free or paid version. It is especially effective at detecting malware, adware, PUPs (potentially unwanted programs), and traces of infections that other antivirus programs miss.

The free version is more than enough for most users as an on-demand scanning tool : it installs, updates, and runs a full scan when an infection is suspected. The premium edition adds real-time features and other advanced options, but for basic diagnostics, the free version is usually sufficient.

ClamWin is another interesting alternative. It's an open-source antivirus whose interface may seem outdated, but it stands out for its ability to detect malware and malicious software with an engine constantly improved by the community. It integrates well with manual scans of folders, removable drives, or specific files.

Alongside these solutions, ESET SysInspector deserves special mention . This free diagnostic tool can be used independently or integrated into ESET products for home, endpoints, and servers running on MS Windows. It's not a typical antivirus, but rather a deep system analyzer.

SysInspector gathers extremely detailed information about running processes, registry entries, loaded drivers, network connections, services, and critical components . From this data, it generates a risk-rated report for each item, helping to identify suspicious components that may be related to malware or conflicts. For persistent infections, it is helpful to supplement these scans with guides on ransomware.

Using these types of security tools focused on analysis, you can obtain a "snapshot" of your system that goes beyond a simple "no viruses found," which is essential when your PC is behaving strangely, there are odd connections, or performance degrades without apparent explanation.

Backup, Microsoft account, and synchronization: essential context

Beyond the technical diagnosis, there's a practical aspect that shouldn't be overlooked: keeping your data safe and your work environment synchronized. In Windows 11, signing in with a Microsoft account offers advantages that indirectly facilitate recovery after a serious failure.

By using that account, you can sync passwords, favorites, Microsoft Edge browser settings, reading lists, themes, and other preferences across devices. This means that if you need to reinstall or switch computers, your user experience will be restored much faster, without having to rebuild everything manually.

Furthermore, you can automatically save your photos and files to OneDrive , so they're protected in the cloud and accessible from any device. In a scenario where a hard drive starts to fail (something you can detect with CrystalDiskInfo) or the system becomes unstable after an update, having up-to-date backups in the cloud greatly reduces the impact.

In terms of diagnostics, this means you can focus on repairing the system without panicking about losing important documents, knowing that much of your personal data is already backed up off-site. And if formatting is necessary, the return to normal will be considerably less traumatic.

Whether we like the integration with the Microsoft account or not, taking advantage of the synchronization and backup options is a logical complement to all the diagnostic tools mentioned, because it minimizes the consequences of the failures that these tools help to detect.

Reviewing all these utilities—from performance monitors like Performance Monitor and Sysmon, to hardware testers like HWiNFO, CrystalDiskInfo, and Memory Diagnostic, to network and security tools like WiFi Analyzer, SoftPerfect Network Scanner, Malwarebytes, ClamWin, and ESET SysInspector—it's clear that Windows 11 offers a very powerful ecosystem for understanding what's happening on your PC . They won't always automatically fix every problem (especially after conflicting updates), but combining them with good backup practices, Microsoft account synchronization, and, if necessary, manual system file repairs puts you in a much stronger position to prevent occasional glitches from turning into full-blown disasters.