Ntdll.dll is an NT layer DLL (Dynamic Link Library) file that contains NT kernel functions. The ntdll.dll file is an essential part of the Microsoft Windows operating system and if this file is absent, your Windows computer will not function properly.
By default, the ntdll.dll file is located in the %system% directory.
Note: %system% is a variable and points to the system directory on your computer. By default, for Windows XP/Vista it is C:\Windows\System32, and for Windows NT/2000 it is C:\Winnt\System32.
Ntdll.dll Error Messages
The following are a few examples of common ntdll.dll error messages that you may encounter after you install Windows, when you try to run Microsoft Internet Explorer, or at other times:
“STOP: C0000221 unknown hard error \SystemRoot\System32\ntdll.dll”
“STOP: 0xC0000221 unknown hard error C:\Winnt\System32\Ntdll.dll"
“<PROGRAM NAME> caused a fault in module NTDLL.DLL at <Memory Address>”
Let us now have a look at some of the common causes of ntdll.dll errors and what you can do to fix them.
Reinstall the program that is generating the ntdll.dll error
In case the ntdll.dll error occurs only with a particular program, reinstalling the program may fix the error.
To do this, first completely uninstall the program that is generating the ntdll.dll error, restart Windows, and then reinstall the program.
Perform repair installation of Windows
If the error persists, perform a repair installation of Windows. A repair installation of
Windows will replace the ntdll.dll file with the correct version and fix the error if the cause of the error was a damaged or corrupt ntdll.dll file.
Update your drivers
The ntdll.dll error may also occur if your drivers are outdated. To repair the error in this case, update your device drivers and ensure that you are using drivers that are compatible with your operating system and hardware.
Remove Internet Explorer Add-ons
In case the ntdll.dll error is appearing when you start or close Internet Explorer, chances are that an add-on is causing the error.
To identify the culprit, selectively disable Internet Explorer Add-ons. To disable an add-on, perform the following steps:
- Open Internet Explorer, click Tools, and then click Internet Options.
- Next, click the Programs tab.
- Now, click the Manage add-ons button.
- Select the first add-on and click the Disable button.
- Restart Internet Explorer.
Repeat the above steps for all the enabled add-ons to identify which add-on is the culprit.
You may also receive ntdll.dll errors if the cable that connects your hard disk to the motherboard is defective. To determine if this is the case, connect your hard disk to another cable of the same type. If the error doesn’t occur, you need to change the cable that connects the hard disk to the motherboard to fix the ntdll.dll error.
If the ntdll.dll error is occurring soon after you have installed Windows, chances are that Windows installation is corrupt. This may happen if you are installing Windows using a pirated CD or when the installation CD is scratched or damaged.
To resolve the issue, format your computer and perform a Windows installation again using an original and unscratched Windows installation CD.