Method 1: Fixing the DLL Error by Copying the Nvapi9x.dll Library to the Windows System Directory 

1. The file you downloaded is a compressed file with the ".zip" extension. In order to install it, first, double-click the ".zip" file and open the file. You will see the library named "Nvapi9x.dll" in the window that opens up. This is the library you need to install. Drag this library to the desktop with your mouse's left button.

   

2. Copy the "Nvapi9x.dll" library you extracted and paste it into the "C:\Windows\System32" directory.

   

3. If your operating system has a 64 Bit architecture, copy the "Nvapi9x.dll" library and paste it also into the "C:\Windows\sysWOW64" directory.

   NOTE! On 64 Bit systems, the dynamic link library must be in both the "sysWOW64" directory as well as the "System32" directory. In other words, you must copy the "Nvapi9x.dll" library into both directories.

   

4. In order to run the Command Line as an administrator, complete the following steps.

   NOTE! In this explanation, we ran the Command Line on Windows 10. If you are using one of the Windows 8.1, Windows 8, Windows 7, Windows Vista or Windows XP operating systems, you can use the same methods to run the Command Line as an administrator. Even though the pictures are taken from Windows 10, the processes are similar.

   1. First, open the Start Menu and before clicking anywhere, type "cmd" but do not press Enter.
   2. When you see the "Command Line" option among the search results, hit the "CTRL" + "SHIFT" + "ENTER" keys on your keyboard.
   3. A window will pop up asking, "Do you want to run this process?". Confirm it by clicking to "Yes" button.

   

5. Paste the command below into the Command Line that will open up and hit Enter. This command will delete the damaged registry of the Nvapi9x.dll library (It will not delete the file we pasted into the System32 directory; it will delete the registry in Regedit. The file we pasted into the System32 directory will not be damaged).

   %windir%\System32\regsvr32.exe /u Nvapi9x.dll

   

6. If you are using a 64 Bit operating system, after doing the commands above, you also need to run the command below. With this command, we will also delete the Nvapi9x.dll library's damaged registry for 64 Bit (The deleting process will be only for the registries in Regedit. In other words, the dll file you pasted into the SysWoW64 folder will not be damaged at all).

   %windir%\SysWoW64\regsvr32.exe /u Nvapi9x.dll

   

7. In order to cleanly recreate the dll library's registry that we deleted, copy the command below and paste it into the Command Line and hit Enter.

   %windir%\System32\regsvr32.exe /i Nvapi9x.dll

   

8. If you are using a 64 Bit operating system, after running the command above, you also need to run the command below. With this command, we will have added a new library in place of the damaged Nvapi9x.dll library that we deleted.

   %windir%\SysWoW64\regsvr32.exe /i Nvapi9x.dll

   

9. You may see certain error messages when running the commands from the command line. These errors will not prevent the installation of the Nvapi9x.dll library. In other words, the installation will finish, but it may give some errors because of certain incompatibilities. After restarting your computer, to see if the installation was successful or not, try running the program that was giving the dll error again. If you continue to get the errors when running the program after the installation, you can try the 2nd Method as an alternative.

Method 2: Copying the Nvapi9x.dll Library to the Program Installation Directory 

1. First, you must find the installation directory of the program (the program giving the dll error) you are going to install the dynamic link library to. In order to find this directory, "Right-Click > Properties" on the program's shortcut.

   

2. Open the program installation directory by clicking the Open File Location button in the "Properties" window that comes up.

   

3. Copy the Nvapi9x.dll library into this directory that opens.

   

4. This is all there is to the process. Now, try to run the program again. If the problem still is not solved, you can try the 3rd Method.

Method 3: Uninstalling and Reinstalling the Program That Is Giving the Nvapi9x.dll Error 

1. Push the "Windows" + "R" keys at the same time to open the Run window. Type the command below into the Run window that opens up and hit Enter. This process will open the "Programs and Features" window.

   appwiz.cpl

   

2. On the Programs and Features screen that will come up, you will see the list of programs on your computer. Find the program that gives you the dll error and with your mouse right-click it. The right-click menu will open. Click the "Uninstall" option in this menu to start the uninstall process.

   

3. You will see a "Do you want to uninstall this program?" confirmation window. Confirm the process and wait for the program to be completely uninstalled. The uninstall process can take some time. This time will change according to your computer's performance and the size of the program. After the program is uninstalled, restart your computer.

   

4. 4. After restarting your computer, reinstall the program that was giving you the error.
5. You may be able to fix the dll error you are experiencing by using this method. If the error messages are continuing despite all these processes, we may have a issue deriving from Windows. To fix dll errors deriving from Windows, you need to complete the 4th Method and the 5th Method in the list.

Method 4: Fixing the Nvapi9x.dll error with the Windows System File Checker 

1. In order to run the Command Line as an administrator, complete the following steps.

   NOTE! In this explanation, we ran the Command Line on Windows 10. If you are using one of the Windows 8.1, Windows 8, Windows 7, Windows Vista or Windows XP operating systems, you can use the same methods to run the Command Line as an administrator. Even though the pictures are taken from Windows 10, the processes are similar.

   1. First, open the Start Menu and before clicking anywhere, type "cmd" but do not press Enter.
   2. When you see the "Command Line" option among the search results, hit the "CTRL" + "SHIFT" + "ENTER" keys on your keyboard.
   3. A window will pop up asking, "Do you want to run this process?". Confirm it by clicking to "Yes" button.

   

2. Paste the command below into the Command Line that opens up and hit the Enter key.

   sfc /scannow

   

3. This process can take some time. You can follow its progress from the screen. Wait for it to finish and after it is finished try to run the program that was giving the dll error again.

Method 5: Getting Rid of Nvapi9x.dll Errors by Updating the Windows Operating System 

Some programs require updated dynamic link libraries from the operating system. If your operating system is not updated, this requirement is not met and you will receive dll errors. Because of this, updating your operating system may solve the dll errors you are experiencing.

Most of the time, operating systems are automatically updated. However, in some situations, the automatic updates may not work. For situations like this, you may need to check for updates manually.

For every Windows version, the process of manually checking for updates is different. Because of this, we prepared a special guide for each Windows version. You can get our guides to manually check for updates based on the Windows version you use through the links below.

Windows Update Guides 

1. Windows Update Guide
2. Windows 8.1 and Windows 8 Update Guide
3. Windows 7 and Windows Vista Update Guide
4. Windows XP Update Guide