“System Interrupts” climbing to 10, 20, or 30 percent CPU is one of the most confusing readings in Task Manager, because there’s nothing to click on, nothing to end, nothing to uninstall. It’s a ghost process — an accounting bucket for time the CPU spends servicing hardware interrupts. Something in your hardware stack is demanding the CPU’s attention far too often, and a driver is handling those demands badly.

The best way to fix it isn’t a sequence of generic tweaks. It’s a hunt: identify which driver is burning the interrupt time, then fix that specific driver or device. Everything below serves that hunt, in the order that finds the culprit fastest.

Why this happens

  • Buggy device driver: A driver with high DPC latency holds the CPU too long per interrupt — the single most common cause.
  • Failing hardware spamming interrupts: A dying drive, network card, or USB device retrying operations fires interrupt storms.
  • USB device driver issues: Poorly written USB peripheral drivers are notorious interrupt hogs.
  • Outdated BIOS/firmware: Interrupt routing and power management bugs fixed in BIOS updates.
  • Network adapter interrupt moderation disabled: The NIC firing an interrupt per packet instead of batching them.
  • Storage controller driver problems: AHCI/NVMe drivers mishandling completion interrupts.
  • Audio driver DPC spikes: Realtek and similar audio drivers with known latency bugs on certain versions.
  • Hardware actually failing: Interrupts are how hardware asks for help; broken hardware asks constantly.

How to fix it

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

Fix 1: Confirm the pattern and check the easy correlation

Watch System Interrupts in Task Manager for ten minutes during normal use. Note whether it’s constant or spiky, and test the obvious correlations: unplug all USB devices (does it drop?), disconnect from Wi-Fi/Ethernet (network driver?), close the laptop lid peripherals. If unplugging a specific device drops the CPU, you’ve skipped straight to the answer — that device or its driver is the problem. This five-minute test resolves a surprising number of cases outright.

  1. Observe System Interrupts CPU for 10 minutes; note constant vs. spiky.
  2. Unplug all USB devices and re-observe.
  3. Disconnect network (Wi-Fi off, Ethernet unplugged) and re-observe.
  4. If a specific device correlates, focus all effort on its driver.

Fix 2: Identify the driver with LatencyMon

Download LatencyMon (free, Resplendence) and run it for 5-10 minutes while the problem occurs. Check the Drivers tab sorted by DPC count and execution time — the driver at the top with huge numbers is your culprit. Typical offenders: network drivers (ndis.sys with a bad NIC driver underneath), storage drivers (storport.sys), audio (portcls.sys), USB (usbport.sys). Write down the exact driver file name; it’s the target for everything below. This is the single highest-value diagnostic step for this problem.

  1. Download and run LatencyMon as administrator.
  2. Let it collect data for 5-10 minutes during the problem.
  3. Open the Drivers tab; sort by DPC count.
  4. Note the top driver file name — that’s your target.

Fix 3: Update or roll back the identified driver

In Device Manager, find the device behind the driver file LatencyMon named. First try updating: right-click → Update driver → Search automatically. If the problem started after a driver update, do the opposite — Roll Back Driver in the device’s Properties → Driver tab. For network and audio drivers especially, get the version from your laptop maker’s support page (Dell , or the equivalent HP or Lenovo site) rather than Windows Update, since OEM versions carry hardware-specific fixes. The troubleshooting walkthrough covers additional driver-hunt techniques if LatencyMon’s answer is ambiguous.

  1. In Device Manager, locate the device for the LatencyMon-identified driver.
  2. Try Update driver first; test for a day.
  3. If the issue began after an update, use Roll Back Driver instead.
  4. Prefer OEM driver versions from the laptop maker’s site for NIC/audio.

Fix 4: Tune the network adapter if it’s the culprit

If the offender is network-related, open the adapter’s Properties → Advanced tab in Device Manager. Enable Interrupt Moderation and set the moderation rate to Adaptive or Medium. Disable power-saving features that cause interrupt churn (Energy Efficient Ethernet, Green Ethernet). Update or replace the driver as in Fix 3. A NIC firing an interrupt per packet on a busy network can single-handedly pin System Interrupts — moderation batches them and the CPU cost collapses.

  1. Open the network adapter’s Properties → Advanced tab.
  2. Enable Interrupt Moderation; set rate to Adaptive.
  3. Disable Energy Efficient Ethernet / Green Ethernet options.
  4. Test under normal network load and compare.

Fix 5: Update the BIOS and chipset drivers

Interrupt routing is partly firmware’s job, and BIOS updates routinely fix interrupt and power-management bugs. Check your laptop maker’s support page for a BIOS newer than yours, and install the latest chipset driver package at the same time. Follow the BIOS update instructions exactly — plugged in, no interruptions. This is especially relevant if the problem appeared after a Windows feature update, which can expose firmware bugs the old OS version masked.

  1. Check your current BIOS version (msinfo32).
  2. Compare against the latest on the manufacturer’s support site.
  3. Install the latest chipset driver package.
  4. Apply the BIOS update following instructions exactly (AC power, no interruptions).

Fix 6: Test hardware by elimination

If drivers check out, suspect the hardware itself. Boot into Safe Mode — if System Interrupts is calm there, it’s a third-party driver (narrow with Fix 2’s method). Test with the battery removed if removable, try a different power adapter, and disconnect internal devices you can (SD cards, secondary drives). For desktops, reseat cards and RAM. A device that’s electrically failing generates interrupts no driver can fix — the answer becomes replacement, and knowing which device saves you from replacing the wrong one.

  1. Boot into Safe Mode; compare System Interrupts CPU.
  2. Remove/detach peripherals one at a time (SD cards, USB devices, docks).
  3. Try a different power adapter if available.
  4. The device whose removal fixes it needs replacement. If disk active time is pinned at 100 percent during these tests, treat that as confirmation of storage distress.

Fix 7: Disable the device as a last resort

If you’ve identified a non-essential device with no working driver (an old fingerprint reader, a flaky SD card reader, a secondary network adapter), disable it in Device Manager rather than letting it burn CPU forever. Right-click → Disable device. This is a pragmatic trade: losing a feature you don’t use to reclaim 15% CPU is a good deal. For essential devices (storage controller, primary NIC) with no fix, the honest answer is hardware replacement — check warranty status before spending money. Intel’s driver detection tool can help verify chipset-side currency.

  1. In Device Manager, right-click the identified non-essential device.
  2. Choose Disable device and confirm.
  3. Verify System Interrupts CPU drops and stays down.
  4. For essential devices with no driver fix, pursue warranty or replacement.

Closing

System Interrupts is the CPU’s way of pointing at a hardware problem it can’t name. The best fix is the directed one: correlate, measure with LatencyMon, and fix the specific driver or device — not a shotgun blast of generic tweaks. Most hunts end at Fix 3 with a driver update or rollback. The rest end with a device identified and either replaced or disabled. Either way, the ghost process goes quiet because the hardware stopped shouting.

Frequently asked questions

What exactly are System Interrupts?
System Interrupts isn’t a real program — it’s a placeholder Task Manager uses for the CPU time spent handling hardware interrupts and deferred procedure calls (DPCs). Every piece of hardware signals the CPU when it needs attention, and the CPU pauses to handle it. Normally this is under 2% of CPU. When a driver handles interrupts badly — taking too long per interrupt — the placeholder’s CPU percentage climbs, and that’s what you’re seeing.
Can I end the System Interrupts process?
No — there’s nothing to end. It’s not a process but an accounting category for kernel-level interrupt handling. The CPU time is real, but it’s being spent inside drivers on behalf of hardware. The fix is finding which driver or device is generating excessive interrupts and fixing, updating, or disconnecting it. Killing is not an option because there’s no process to kill.
Is System Interrupts high CPU a virus?
Essentially never. Malware doesn’t manifest as interrupt load — it runs as processes you’d see by name. System Interrupts high CPU is a driver or hardware issue in the overwhelming majority of cases: a buggy driver, a failing device spamming interrupts, or a misbehaving USB peripheral. Run a malware scan for peace of mind, but put your effort into drivers and devices.
Why does it get worse when I plug in a USB device?
Because that device’s driver is likely the source. USB devices generate interrupts for every transfer, and a buggy driver or a failing device can generate far more than it should — a dying USB drive retrying reads, for example, fires interrupt storms. If the CPU spike tracks a specific device, you’ve found your culprit: update its driver, try a different port, or replace the device.