Error "npptools.dll missing" when installing a diagnostic tool.

There are several different ways that npptools.dll errors can show up on your computer.

Here are some of the more common ways that you might see npptools.dll errors:

"Npptools.dll Not Found".

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

"Cannot find [PATH]\npptools.dll"

"The file npptools.dll is missing."

Npptools.dll errors are caused by situations that lead to the removal or corruption of the npptools DLL file.

In some cases, npptools.dll errors could indicate a registry problem, a virus or malware issue or even a hardware failure.

If you are looking for a specific version of this file from an external source, I would suggest you not to do that.

You should not download the missing or corrupted dll files from "DLL download" websites. There are several reasons why downloading a DLL file is a bad idea.

If you need a copy of npptools.dll, I suggest that you follow the steps as it is a legitimate source to get the file:

Method 1:

Reinstall the program that uses the npptools.dll file. 

If the npptools.dll DLL error occurs when you use a particular program, reinstalling the program should replace the file.

Important: Try your best to complete this step.

Reinstalling the program that provides the npptools.dll file, if possible, is a likely solution to this DLL error.

Method 2:

I would suggest you to perform SFC scan and check if that helps. The SFC /scannow command scans all protected system files and replaces incorrect versions with correct Microsoft versions.