If you’ve ever had a sluggish PC, you might have dropped into Task Manager only to see nothing alarming. CPU and RAM seem fine and no obvious processes were misbehaving. The next step, then, should be dropping into the Run dialog with a command and letting Windows spend a minute reporting exactly what’s going on. The tool generates solid information that will clue you in to whatever’s going on with your PC.
Performance Monitor has been part of Windows since Windows NT and you may know it as the thing with all the scrolling graphs. What you might have missed is that it ships with a built-in System Diagnostics report that collects 60 seconds of data to generate a full color-coded breakdown of your CPU, memory, disk, network, software config, and hardware state. It also offers up plain-English warnings and suggestions, and it all happens right on your machine.
How to run it
Hit Win + R and type perfmon /report
To get this great report, simply hit Win + R to open the Run dialog, then type perfmon /report. Hit Enter and Windows will open Performance Monitor and immediately start collecting data. You’ll see a progress bar (Collecting Data) run for about a minute, and you’ll want to just leave it be without multitasking on your PC, as that will get you better results.
Once that finishes, the report opens automatically inside Performance Monitor, but it’s also an HTML file saved locally to C:\PerfLogs\System\Diagnosticsso you can close and reopen it later without having to rerun the command.
If you get a permissions dialog, accept it. The tool needs elevated access to read some system counters.
The Diagnostic results section at the top uses a color-coded system, with green for checks that passed, yellow for warnings you might want to check out, and red for items that need your attention. THis is the fastest way to see if you have a real problem or just have a noisy background process.
Below that are two subsections. Basic System Checks will figure out what services are running, whether any devices are throwing errors, and whether security settings are misconfigured. The Performance section shows which processes were the top users of CPU, disk, network, and memory during that 60 seconds. You can find the process using up more resources than it should, even if Task Manager looks ok.
What each section tells you
Software Configuration, Hardware Configuration, and the resource sections
Software Configuration covers your OS version, Security Center state, running services, and startup programs. If a service set to run at startup is causing problems, it shows up here. Hardware Configuration goes deeper: disk health, BIOS version, device states, and Windows Experience Index scores. If a driver is outdated or a device is in an error state, this is where it gets flagged.
The CPU section shows average processor time and processor queue length (threads waiting to run). Anything consistently above 2 per core suggests a bottleneck. The Memory section shows available RAM and pages per second; high pages/sec values mean the system is swapping memory to disk, which can tank performance. Disk covers read/write throughput and average response times. Network shows bytes in and out per adapter. Every flagged item links to Microsoft documentation for next steps, which can be more useful than it sounds.
Once you’ve figured out what’s going wrong, start with any red items in the Diagnostic Results section. Yellow warnings are worth investigating, but might not be the direct cause of any slowdowns.
For CPU issues, cross-reference the top process list with Task Manager’s Details tab to confirm the problem issue, then decide whether to disable (temporary fix) or uninstall (more permanent). Check whether pages/sec is consistently high, which could point to needing more RAM or having a memory-hungry process running unchecked. Look at the top disk processes to figure out the issue there. Disk slowdowns often come from a single backup agent or even an antivirus scanner.
Once you make those changes, run perfmon / report again and compare. The reports come with a timestamp, and older runs stay in C:\PerfLogs\System\Diagnosticsfor reference.
What perfmon /report won’t catch
There are still limits
This report is only a 60-second snapshot, so intermittent problems (like going to the mechanic, right?) that don’t happen to occur during the time period won’t show up in the report. It also doesn’t flag kernel-lever driver issues or deeper I/O problems; you’ll need Windows Performance Recorder for those.
If you want a historical view of crashes, failed updates, or application errors over time, run perfmon /rel to open Reliability Monitor instead. It can complement your Performance Monitor report when tracking down any issues on your PC.
It’s worth running before calling anything broken
Most of the time, troubleshooting a slow PC is a guessing game, where you disable apps on startup, reboot, and see if it feels better. That can take a lot of time (ask me how I know). Instead, perfmon /report gives you a structured, documented snapshot of your system in about a minute, with color-coded warnings and the names of what’s causing the issues. It’s been in there since before Windows 10, so it’s time to use it.