Use These Free Windows Tools to Find What’s Slowing Down Your PC

Windows Device Performance and Health

Let’s start with the simplest way to check your computer’s overall condition. The Windows Device Performance & Health feature is my go‑to tool for an initial check. Whenever I feel something isn’t performing well, I open this tool and quickly look for yellow warning icons. It lets me review storage capacity, battery health, potential app issues, and whether my system time is properly synced.

To visit it, press the Windows key, type “Windows Security”, and hit Enter. When Windows Security opens, click Device performance & health. The interface shows a simple dashboard with green checkmarks when everything is working properly, or yellow warning icons when something needs attention.

In this example, the Storage capacity section warns me that I’m running low on disk space. I’ve learned that Windows needs at least 20 percent of my storage drive space free to run efficiently. So after seeing the warning here, I clicked See more info and accessed Windows’ storage settings, where I could easily clean up files.

I also find the Battery life section incredibly useful on my laptop. It shows which apps are draining the battery more than they should and suggests ways to extend battery life. Though it’s not as powerful as some of the best tools for analyzing laptop battery, it’s still my favorite because it’s simple to use and is already baked into Windows. These types of tools are especially helpful when I forget my charger while I’m out writing for the day.

Windows Resource Monitor

Windows Resource Monitor is my go-to tool whenever I have to diagnose a family member’s sluggish computer. It’s free and comes installed as part of the OS, making it convenient to use. This feature allows me to get real-time data about everything that consumes system resources.

To access Resource Monitor, press the Windows key, type “resmon”, and hit Enter. You can also access it through Task Manager (Ctrl + Shift + Esc) by clicking the Performance tab and then Open Resource Monitor at the bottom.

The Overview tab shows you a complete picture of the system’s health. With this tool, I can see which processes are eating up a system’s CPU, memory, disk, and network resources in one place. This allows me to quickly tell what’s causing the problem.

Just a few days ago, I discovered that Adobe Lightroom was constantly writing to my desktop PC’s storage disk even when I wasn’t using it. On the Disk tab, I saw it under Processes with Disk Activity with massive write operations. It turns out Lightroom Classic was hammering the disk because it was rebuilding previews and updating catalogs in the background. I easily fixed the problem by moving the entire catalog and preview files to a secondary drive and updating Lightroom’s default location for these files.

If I had used only Task Manager’s Performance tab, I would have seen a quick overview of system usage. With Resource Monitor, I identified the exact app and processes causing the slowdown and the files they were hitting.

Windows Memory Diagnostic

RAM problems can make your computer behave in weird ways. I’ve seen systems that randomly freeze, crash with blue screens, or run incredibly slowly because of faulty memory. Windows Memory Diagnostic helps me test RAM without needing any third-party software.

Open this tool by pressing Win + R, then typing “mdsched.exe” and pressing Enter. The Windows Memory Diagnostic window pops up with two options; I usually choose Restart now and check for problems because I want immediate results.

The computer will reboot and show a blue screen with a progress bar. If I want to be thorough, I press F1 during the test to access advanced options. Here, I can choose Extended testing and increase the number of passes.

After the test completes and Windows boots up, I check the results in Event Viewer. I press Win + X, select Event Viewer, expand Windows Logs, click System, then use Ctrl + F to search for “MemoryDiagnostics-Results”.