It’s the strangest entry in Task Manager: System Interrupts, using 15%, 25%, sometimes 40% of your CPU — and there’s no app to close, no service to stop, no file to delete. That’s because System Interrupts isn’t a program at all. It’s Windows telling you the CPU is spending its time answering hardware interruptions, over and over, from some device or driver that won’t quiet down.

Fixing it means playing detective: the interrupts are a symptom, and the disease is a misbehaving driver or failing hardware. The tools are built into Windows — Task Manager for the symptom, LatencyMon or Windows Performance Analyzer for the culprit. For the deep-dive diagnostic methodology, see troubleshooting System Interrupts ; for CPU issues with identifiable processes, high CPU usage in Windows 11 covers those.

You can do this without special expertise — just patience and process of elimination.

Why this happens

  • Faulty or outdated device driver: The top cause — a buggy network, audio, or storage driver mishandles interrupts, generating storms of them.
  • Failing USB device: A dying flash drive, bad dock, or flaky peripheral can fire thousands of interrupts per second.
  • Storage controller issues: AHCI/RAID driver bugs or a struggling drive generate excessive disk-completion interrupts.
  • Network adapter interrupt moderation off: Without moderation, high network traffic means an interrupt per packet — crippling on gigabit transfers.
  • BIOS/firmware bugs: Power-management firmware bugs can cause interrupt storms, especially around sleep/wake or CPU state changes.
  • Failing hardware: A dying Wi-Fi card, disk, or motherboard component can signal distress as interrupt floods.
  • DPC latency from audio drivers: Poorly written audio drivers are notorious DPC hogs, showing up as System Interrupts load.

How to fix it

Work through these in order — diagnose first, then act.

Fix 1: Confirm and quantify the problem

Make sure you’re chasing a real issue, not a momentary spike.

  1. Open Task Manager and watch System Interrupts for five full minutes at idle.
  2. Sustained double digits at idle is abnormal; brief spikes during file copies are not.
  3. Note whether it correlates with anything: Wi-Fi activity, USB devices plugged in, audio playing.
  4. This baseline tells you later whether fixes worked.

Fix 2: Unplug all USB devices

The fastest high-yield test — USB is the most common interrupt-storm source.

  1. Disconnect every USB device: drives, docks, printers, receivers, hubs.
  2. Watch System Interrupts for two minutes.
  3. If CPU drops, reconnect devices one at a time, waiting a minute each, until the culprit reveals itself.
  4. Replace or update the driver for the offending device.

Fix 3: Update drivers systematically

Work through the usual suspects in order: network, audio, storage, chipset.

  1. Update network adapter drivers first — the most common DPC offenders.
  2. Then audio drivers, then storage/chipset drivers.
  3. Use manufacturer sources: Intel Intel’s driver detection tool , NVIDIA NVIDIA’s driver download page , or your laptop maker’s support page.
  4. Restart after each driver family and re-check before moving on.

Fix 4: Use LatencyMon to identify the driver

When elimination fails, measure precisely which driver is stalling.

  1. Download LatencyMon (free, Resplendence) and run it for 5-10 minutes.
  2. Check the Drivers tab sorted by DPC count — the top entries are your suspects.
  3. The reported driver filename (e.g., ndis.sys, storport.sys, a vendor .sys) names the culprit.
  4. Update, roll back, or disable the device using that driver.

Fix 5: Disable problematic devices

If a driver can’t be fixed, the device can be sidelined.

  1. Open Device Manager and find the suspect device.
  2. Right-click and choose Disable device (for non-essential hardware like a secondary network adapter).
  3. For essential devices, try Roll Back Driver on the Driver tab first.
  4. Re-check System Interrupts after each change.

Fix 6: Update BIOS and chipset firmware

Firmware-level interrupt bugs need firmware-level fixes.

  1. Check your manufacturer’s support page for BIOS updates mentioning stability or interrupt fixes.
  2. Install following instructions exactly, with the charger connected.
  3. Also update chipset drivers from the manufacturer or Intel/AMD.
  4. Microsoft’s guidance at Microsoft’s Windows support site covers update best practices.

Fix 7: Test hardware health

When software fixes fail, suspect the hardware itself.

  1. Run your manufacturer’s hardware diagnostics (most have built-in boot-time tests).
  2. Check SMART data for storage drives.
  3. Test with a Linux live USB — if interrupts are high there too, it’s hardware, not Windows.
  4. Failing Wi-Fi cards and dying drives are the most common hardware culprits.

Fix 8: Test with CPU power states disabled

On some laptops, interrupt storms come from buggy C-state transitions — the CPU entering and exiting low-power states generates interrupt traffic that a firmware bug multiplies. Disabling deep C-states is a diagnostic, not a permanent fix, but it’s conclusive.

  1. Enter BIOS/UEFI setup during boot (F2, Del, or your manufacturer’s key).
  2. Find CPU power management options — look for C-States, Processor C-State, or Package C-State settings.
  3. Disable them temporarily (or limit to C1) and boot into Windows.
  4. Watch System Interrupts for ten minutes at idle. If it drops to near zero, you’ve found a firmware power-management bug.
  5. Re-enable C-states afterward — disabling them permanently costs battery life and generates heat.
  6. The real fix is a BIOS update addressing the C-state bug; report the finding to your manufacturer’s support with your measurements.
  7. If nothing changes, re-enable C-states and continue with the driver isolation above — you’ve ruled out one more cause.

Closing

System Interrupts is Windows waving a flag: some hardware is shouting too much. The fix is detective work — unplug USB devices, update drivers in suspect order, and use LatencyMon when guessing fails. Most cases resolve to one bad driver or one dying peripheral. Find it, fix or remove it, and that phantom CPU usage vanishes back to the near-zero where it belongs.

Frequently asked questions

What is the System Interrupts process?
System Interrupts isn’t a real program — it’s Task Manager’s display name for CPU time spent handling hardware interrupts and deferred procedure calls (DPCs). When hardware needs the CPU’s attention (a packet arrives, a disk read completes), the CPU pauses to handle it. Normal systems show 0-2%; sustained high percentages mean some hardware or driver is interrupting far too often.
Is System Interrupts a virus?
No. It’s a built-in Windows accounting entry, not an executable — there’s no file to infect. Malware can’t ‘be’ System Interrupts, though malware activity could theoretically cause interrupt load indirectly. If someone tells you to download a tool to ‘remove System Interrupts,’ that’s the actual scam. The real fix is finding the misbehaving driver or device.
What's a normal System Interrupts CPU percentage?
At idle, under 1-2% is normal, with brief spikes to 5-10% during heavy I/O. Sustained 10-20%+ at idle is abnormal and worth investigating; 30%+ usually points to a specific faulty driver or device. Laptops on battery sometimes show slightly higher numbers due to power-state transitions, but not dramatically.
Can a USB device cause high System Interrupts?
Absolutely — it’s one of the most common causes. A failing USB drive, a problematic dock, or a device with a bad driver can generate thousands of interrupts per second. The classic diagnostic: unplug all USB devices and watch the CPU drop. If it does, reconnect them one at a time to find the offender. Faulty USB hardware is behind a surprising share of these cases.