How to Fix ndis.sys Failed BSOD on Windows 11

The ndis.sys failed BSOD usually comes from a network adapter driver, a recent driver or failed Windows update, damaged system files, or faulty hardware. Start Windows in Safe Mode if needed, repair the network driver, and then check Windows files, the system disk, restore points, and hardware in that order. 

What Causes ndis.sys Failed in Windows 11?

Ndis.sys is a protected Windows component that helps the operating system communicate with network adapter drivers. When it appears on a blue screen, the actual problem may come from another driver or hardware component using the Windows networking layer.

The most common cause is a damaged, outdated, or incompatible network adapter driver, especially after a driver or Windows update. Other possible causes include corrupted system files, RAM errors, disk problems, or a failing network adapter.

Do not delete ndis.sys or download a replacement from a third-party website. The file must match your Windows version and build, so use the fixes below to repair the related driver or system component instead.

How to Fix ndis.sys Failed BSOD on Windows 11

Start with the method that matches when the blue screen began. Test the computer after each change so that you can identify what fixed the ndis.sys failed BSOD instead of applying every method at once.

Way 1. Enter Safe Mode If Windows Keeps Crashing

Safe Mode loads a reduced set of Windows drivers and services. It provides a more stable environment for removing a bad driver or reversing a recent system change.

If Windows can reach the sign-in screen:

Step 1. Hold Shift while selecting Power > Restart.

Step 2. Select Troubleshoot > Advanced options > Startup Settings.

Step 3. Click Restart.

Step 4. Press 4 or F4 to start Safe Mode.

If Windows repeatedly crashes before the sign-in screen, interrupt startup two or three times to open the Windows Recovery Environment. Then follow the same path through Advanced options and Startup Settings.

Choose ordinary Safe Mode first. Safe Mode with Networking loads additional network components that may reproduce the same crash. Once Safe Mode opens, continue with the driver and update methods below.

If the computer stays stable in Safe Mode but crashes during a normal startup, a loaded driver or recently installed component is more likely to be the culprit.

Way 2. Update, Roll Back, or Reinstall the Network Adapter Driver

The network adapter driver should be the first component checked after reaching Windows. Choose update, rollback, or reinstall based on what happened before the blue screen appeared.

Before removing the current driver, download a suitable replacement from the computer, motherboard, or network adapter manufacturer. Save it locally or on a USB drive so that it remains available if the computer cannot connect to the internet.

Step 1. Right-click Start and open Device Manager.

Step 2. Expand Network adapters.

Step 3. Right-click the Wi-Fi or Ethernet adapter and select Update driver.

Step 4. Check Windows Update for optional driver updates.

Step 5. If Windows does not provide a suitable version, install the driver downloaded from the device manufacturer.

Step 6. Restart Windows and test the computer.

If the ndis.sys failed error began after a driver update, open the adapter’s Properties window and select the Driver tab. Use Roll Back Driver when the button is available.

If updating and rolling back do not help, reinstall the driver:

Step 1. Open Device Manager and expand Network adapters.

Step 2. Right-click the affected adapter and select Uninstall device.

Step 3. Select the option to remove the driver package if Windows displays it.

Step 4. Restart the computer.

Step 5. Install the driver obtained from the device manufacturer.

Avoid automatic driver updater programs. They may install a generic or mismatched network driver that is newer by date but unsuitable for the computer’s hardware configuration.

Way 3. Install Windows Updates or Remove a Recent Update

Windows updates can correct driver compatibility and system-file problems, but an update can also expose an existing driver conflict. The correct action depends on when the blue screen started.

If Windows has not been updated recently, open Settings > Windows Update and install available quality and driver updates. Restart the computer even if Windows does not request an immediate restart.

If the BSOD began directly after an update:

Step 1. Open Settings > Windows Update > Update history.

Step 2. Select Uninstall updates.

Step 3. Locate the most recent quality update.

Step 4. Uninstall it and restart Windows.

When Windows cannot start normally, open Windows Recovery Environment and select Troubleshoot > Advanced options > Uninstall Updates. Begin with the latest quality update rather than removing a feature update without evidence.

Do not remove several updates at once. Reversing one recent change and testing the result makes it easier to find the actual trigger.

Way 4. Repair Windows Files with DISM and SFC

Use DISM and System File Checker when the network driver appears correct or when Windows reports other damaged components. DISM repairs the Windows component store, while SFC uses that source to replace protected system files.

Step 1. Open Command Prompt as administrator. Run the following command first:

DISM.exe /Online /Cleanup-Image /RestoreHealth

Step 2. Wait for DISM to finish. Do not close the window if the percentage pauses for several minutes.Next, run:

sfc /scannow

Restart Windows after the scan reaches 100 percent. If SFC reports that it could not complete the operation, repeat the scan in Safe Mode. Do not download a new copy of ndis.sys after SFC finds damage. DISM and SFC use files that match the installed Windows build and are safer than manual file replacement.

Way 5. Scan the Computer for Malware

Run a malware scan when system files change without explanation, Windows Security is disabled, or the blue screen appears with other unusual system behavior. Malware is not the leading cause of this BSOD, so this method should follow the driver and system file checks.

Step 1. Open Windows Security > Virus & threat protection > Scan options. Select Full scan and allow Windows Security to examine the system drive.

If the scan finds nothing but suspicious behavior continues, select Microsoft Defender Offline scan. The computer will restart and scan outside the normal Windows session, so save open work first.

Way 6. Check the System Disk for File-System and Surface Errors

Check the system disk when SFC keeps finding damaged files, Windows reports read errors, or the computer also freezes while opening files. AOMEI Partition Software provides visual checks that help separate file-system errors from possible disk surface problems.

Step 1. Open AOMEI Partition Software. Right-click the system partition and select Advanced > Check Partition.

Step 2. Select the option to check and fix file-system errors.

Step 3. Confirm the operation and restart if the program needs exclusive access to the partition.

You can also select the physical system disk and open Test > Disk Surface Test. The scan displays readable blocks and blocks that return errors, making the result easier to review than a long command-line report.

Disk Surface Test detects possible bad sectors but does not repair physical damage. If the scan finds reading errors, protect important files and check the drive’s health before placing more load on it.

This method does not repair ndis.sys or the network adapter driver directly. It helps identify storage problems that may be causing Windows system files to become damaged again.

Way 7. Restore Windows to a Point Before the BSOD

System Restore is useful when the ndis.BSOD started after a driver, application, or Windows setting changed. It returns system files, drivers, installed programs, and registry settings to an earlier state without normally deleting personal files.

Step 1. Press Win + R, enter rstrui.exe, and select OK. Choose a restore point created before the blue screen first appeared, select Scan for affected programs, and review what will be removed.

Step 2. If Windows cannot start normally, open Windows RE and select Troubleshoot > Advanced options > System Restore. A BitLocker recovery key may be required on an encrypted device.

System Restore depends on an existing restore point. If no suitable point is available, continue to the hardware checks instead of using an unknown registry cleaner.

Way 8. Test Memory and the Network Adapter Before Replacing Hardware

Hardware testing belongs at the end because an ndis.sys failed BSOD does not prove that the network card is broken. Test the memory and isolate the adapter before buying replacement parts.

Step 1. Press Win + R.

Step 2. Enter mdsched.exe

Step 3. Select Restart now and check for problems. Allow Windows Memory Diagnostic to complete the test.

Step 4. Check the result after Windows restarts.

Replace the internal network adapter only when the system remains stable with the original adapter disabled and the error returns after it is enabled. On a computer with an integrated adapter, the fault may also involve the motherboard, so professional hardware testing may be needed.

Ending

The most effective repair order is Safe Mode, network driver repair, Windows Update review, DISM and SFC, and then conditional disk or hardware checks. This sequence addresses the likely cause first without replacing protected Windows files or buying hardware too early.

AOMEI Partition Software becomes useful when the BSOD is accompanied by repeated file corruption or disk reading problems. Its partition, surface, and disk health checks can identify a storage issue that Windows driver repair alone would not address.

FAQs About ndis.sys Failed

1. What is ndis.sys in Windows 11?

Ndis.sys is a Microsoft Windows system file used by the Network Driver Interface Specification. It helps Windows network protocols communicate with Wi-Fi, Ethernet, Bluetooth networking, and other network adapter drivers. Seeing the filename in a crash report does not always mean the file is defective. Another driver, invalid memory access, or failing hardware may have caused the crash while ndis.sys was processing a request.

2. Can I delete or replace ndis.sys?

No. Deleting ndis.sys can disable Windows networking or prevent the operating system from starting correctly. Do not download a replacement from a third-party file website. Use DISM and SFC to restore the correct Microsoft-protected version, then repair the driver or hardware that triggered the error.

3. Why does ndis.sys cause DRIVER_IRQL_NOT_LESS_OR_EQUAL?

The DRIVER_IRQL_NOT_LESS_OR_EQUAL stop code means that a kernel-mode driver attempted to access invalid or unavailable memory at the wrong interrupt level. Ndis.sys may appear because the failure happened while Windows was processing network driver data. Start by repairing the network adapter driver. If the computer also produces unrelated stop codes, test the RAM and other hardware because memory corruption can make a working Windows module appear to be the cause.