What is ndistapi?

The genuine ndistapi.sys file is a software component of Windows NDIS 3.0 Connection Wrapper Driver by Microsoft.
"ndistapi.sys" is a Windows kernel driver for USB Telephony Card Devices and is a component of the telephone services function in Windows. The file holds the specific drivers for all unused USB miniports and it reports this info to the TAPI (Telephony Application Programming Interface) system in Windows. It receives teardown and call setup requests from the TAPI provider like AT&T, Cricket, Time warner, Vonage, magicJack® VOIP, Qwest, etc. and then sends those requests to the specific miniport drivers through the NDISWAN (Network Driver Interface Specification Wireless Area Network) for setting up, monitoring, and tearing down lines and calls. Microsoft is a well-known, global corporation that develops innovative devices and software, such as their Windows operating systems and hundreds of PC accessories and devices.

NDISTAPI stands for Network Driver Interface Specification Telephony Application Programming Interface

Ndistapi.sys is a Windows driver. A driver is a small software program that allows your computer to communicate with hardware or connected devices. This means that a driver has direct access to the internals of the operating system, hardware etc. The free file information forum can help you determine if ndistapi.sys is a Windows system file or if it belongs to an application that you can trust.

Run a free scan to check for ndistapi drivers in need of updating

Ndistapi.sys file information

The process known as NDIS 3.0 connection wrapper driver belongs to software Microsoft Windows Operating System by Microsoft (

Description: The original ndistapi.sys is an important part of Windows and rarely causes problems. The ndistapi.sys file is located in the C:\Windows\System32\drivers folder. Known file sizes on Windows 10/8/7/XP are 10,112 bytes (43% of all occurrences), 9,600 bytes, 20,992 bytes, 10,496 bytes or 20,480 bytes. 
The driver can be started or stopped from Services in the Control Panel or by other programs. The ndistapi.sys file is a Windows core system file. The program has no visible window. The file is a Microsoft signed file. ndistapi.sys appears to be a compressed file. Therefore the technical security rating is 1% dangerous, however you should also read the user reviews.

Recommended: Identify ndistapi.sys related errors

Important: Some malware disguises itself as ndistapi.sys, particularly when not located in the C:\Windows\System32\drivers folder. Therefore, you should check the ndistapi.sys process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.


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NdisTapi is a Remote Access NDIS WAN Driver

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Best practices for resolving ndistapi issues

A clean and tidy computer is the key requirement for avoiding problems with ndistapi. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic Update. Always remember to perform periodic backups, or at least to set restore points.

Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or, for Windows 8 and later versions, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the ndistapi.sys process on your computer, the following programs have proven to be helpful: Security Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

ndistapi.sys [all]