Steps To Fix Nssutil3.dll Errors

Nssutil3.dll is a file used by the “Network Security Services” part of Mozilla Firefox. This file is used extensively by the Firefox browser to help it run as smoothly and effectively as possible. However, it’s often the cause of many different errors which can prevent your browser from loading and prevent your PC from running certain applications.

What Caues Nssutil3.dll Errors?

Nssutil3.dll errors can be caused by a series of different problems, including having virus infections, registry errors and a corrupt file. However, the main cause of this problem is down to the way in which some firewall & antivirus programs mistakenly label it as a “Trojan” virus (typically BullGuard and BitDefender). They will then “quarantine” the file, preventing Firefox from actually using it. Here’s the typical error you can see for the this file:

“This application failed to start because nssutil3.dll was not found. Re-installing the application may fix this problem.”

To fix this problem, you should follow the steps below:

How To Fix The Nssutil3.dll Errors

Step 1 – Update Virus Definitions

The first step is to update all the virus definitions for your antivirus programs and then reinstall Firefox. This will allow the antivirus program to recognize nssutil3.dll as a file that’s not got a virus inside and should allow you to run Firefox again.

However, if Firefox does not run after the reinstall, you should then go into BullGuard, Bitdefender or which ever antivirus program you are using and then set an “exception” for nssutil3.dll or Firefox.exe. This should prevent the file from being quarantined and should prevent the error.

However, if the error still shows, you may want to follow the steps below:

Step 2 – Manually Replace Nssutil3.dll On Your System

Replacing the nssutil3.dll file is probably the surest way to get your system running as smoothly as possible again. You can do this very easily by following the guide below:

1) Download nssutil3.zip from our server

2) Unzip the nssutil3.dll file onto your computer’s hard drive

3) Browse to c:\Program Files\Mozilla Firefox**

4) Locate the current nssutil3.dll on your system

5) Rename the current nssutil3.dll to nssutil3BACKUP.dll

6) Copy & paste the new nssutil3.dll into c:\Program Files\Mozilla Firefox**

7) Click Start > Run (Or search”run” on Vista & Win7)

8 ) Type “cmd” in the box that appears

9) Type “regsvr32 nssutil3.dll” on the black screen

10) Press enter

Note: “c:\Program Files\Mozilla Firefox” = the Firefox installation folder for your PC

This will replace the nssutil3.dll file on your PC with a fresh, new copy that your PC should be able to access again.

Step 3 – Clean Out Viruses

– Download This Virus Scanner

Antivirus programs are software tools which scan through your PC and remove any of the viruses or malware infections that are on your system. It’s often the case that viruses will infect various DLL files on your computer and then cause them to be unreadable to your PC. To ensure this is not happening on your computer, you should try using an antivirus program to scan through your system and remove any of the infections that cause all these errors. You can download our recommended antivirus program from the link above, but there are a large variety of programs available.

Step 4 – Clean Out The Registry

– Download This Registry Cleaner

Another big cause of the nssutil3.dll errors is the registry database of Windows. The “registry” is a central database which stores all the settings, information and options for your computer, and is where Windows keeps many vital settings that it requires to run. It’s often the case that a lot of registry settings become damaged and corrupted, leading your PC to take longer to run, making it run slower and with a lot of errors. To fix this problem, you should use a ‘registry cleaner’ to scan through your PC and fix any of the damaged or corrupt settings that are inside it. You can see our recommended registry cleaner below: