ERROR_INTERRUPT_STILL_CONNECTED 0x2FC fix when uninstalling drivers

When you'll see this error

You're in Device Manager, trying to uninstall a driver—maybe an old USB controller, a network card, or a legacy serial port. You right-click, hit Uninstall, and instead of a clean removal, you get that error message: "The specified interrupt vector is still connected." The error code is 0x000002FC. This usually happens on older Windows systems—Windows 7, Windows 8.1, or Windows 10 version 1809 and earlier. It's rare on modern Windows 11 builds, but I've seen it pop up on some Dell Optiplex 3050 and HP EliteDesk 800 G3 machines.

Root cause in plain English

Every hardware device plugged into your motherboard uses an Interrupt Request (IRQ) line to talk to the CPU. Think of IRQs as dedicated phone lines—each device needs one. Problem is, there are only 16 IRQ lines (0-15) on a standard PC, so devices have to share. When you try to uninstall a driver for a device that's sharing its IRQ line with another active device, Windows says "No—that interrupt is still in use." It's protecting the other device from crashing.

The real culprit? Usually a USB controller or a network card that's hardwired to a legacy IRQ (like IRQ 9, 10, or 11) that's also used by a system timer or a PCI bridge. The driver refuses to go until you break that connection.

Step-by-step fix

1. Open Device Manager. Press Win + X, select Device Manager. Or type devmgmt.msc into Run (Win + R).
2. View resources by connection. Click the View menu (top toolbar), select "Resources by connection." This shows you all IRQ assignments. You should see a tree with "Interrupt Request (IRQ)" at the top.
3. Find the problem device. Expand "Interrupt Request (IRQ)" and locate the device you're trying to uninstall. It'll be listed under its IRQ number. For example, if you're uninstalling a Realtek PCIe GbE NIC, you might see it under (IRQ 11). Write down the IRQ number.
4. Check all devices sharing that IRQ. Under the same IRQ number, see what else is there. You'll often find a USB controller, a PCI Express root port, or a High Definition Audio controller sharing the line. That's why the uninstall fails.
5. Disable the sharing device first. Right-click the other device(s) sharing the IRQ, select "Disable device." Confirm the warning. After you do this, you'll see a down arrow on that device icon. This frees the IRQ line.
6. Now uninstall your target device. Right-click the device you originally wanted to remove, select "Uninstall device." Check "Delete the driver software for this device" if you want a clean sweep. Click Uninstall. This time it should complete without the 0x000002FC error.
7. Re-enable the sharing device. Right-click the device you disabled earlier, select "Enable device." It'll grab a different IRQ or reestablish the original line (Windows renegotiates IRQ sharing automatically). Test your system—USB ports should work, audio should play.

If that doesn't work—the nuclear option

Sometimes disabling a device doesn't free the IRQ fast enough. Windows holds the interrupt vector in a "pending disconnect" state. Here's what to try next:

1. Boot into Safe Mode. Restart your PC, press F8 repeatedly during boot (or hold Shift while clicking Restart > Troubleshoot > Advanced Options > Startup Settings > Restart > choose Safe Mode). Safe Mode loads minimal drivers and often releases IRQ locks.
2. Open Device Manager in Safe Mode. Same steps as before. View > Resources by connection. You should see fewer devices listed. The IRQ lines will be almost empty except for core hardware.
3. Uninstall the driver. Right-click the target device, Uninstall. It'll work now because no other device is holding that IRQ.
4. Reboot normally. Windows will detect the missing driver and may reinstall it automatically. If you're trying to remove it permanently (e.g., for a hardware swap), pull the physical card before rebooting.

Still stuck? Check the BIOS

If the error persists even in Safe Mode, the interrupt vector issue is baked into the motherboard's firmware. Go into your BIOS/UEFI settings (press Del, F2, or F10 during boot). Look for "IRQ Resources" or "PCI IRQ Steering." Set it to "Auto" if it's on "Manual." Also disable "Legacy USB Support" if you're uninstalling USB drivers—that setting locks IRQs for old USB 1.1 controllers. Save and exit, then try the uninstall again.

One more thing: if you're using a PCI card (not PCIe), reseat it. Loose connections can cause phantom IRQ assignments that Windows can't release. Shut down, unplug, reseat the card, boot, and retry.