MPCLIENT.DLL, the Windows Defender
Mpclient.dll is a Client Interfacing module belonging to Microsoft Corporation’s Windows Defender. Windows Defender, previously known as Windows Anti-Spyware, is an anti-spyware application capable of scanning the user’s computer systems for a variety of malicious files, including viruses, malware and spyware; it also runs a number of other security features such as personal firewalling. As it is part of a Microsoft program, the mpclient.dll can easily be downloaded from the Microsoft web site.
A singular instance associating the mpclient.dll file with a Trojan has been reported. The issue was first reported with the use of Internet Explorer 7 and was caused by unauthorized downloading. The Trojan, name Zonebac, is no longer a problem, but users must be careful when downloading files from the Internet. Reputed shareware and freeware web sources for acquiring the mpclient.dll file are dll-files and dlldump. No matter how trustworthy a web source is, always run a virus-check before installing any downloaded files on your system.
Errors Regarding mpclient.dll
“mpclient.dll file not found”
Try reinstalling the Windows Defender program; if the problem is not solved, check the program directory for mpclient.dll by going to Search, All Files and Folders, More Advanced Options and selecting Search Hidden Files and Folders. If the file is not available in the program directory, you will need to download it either directly from Microsoft or from a reliable third party web source.
“MSASCui.exe – unable to locate component. This application has failed to start because MpClient.dll was not found”
As mentioned earlier, this error was actually caused by a Trojan in a computer system. While the problem is believed to have been solved, in case it happens to your system, run a virus scan immediately and take the necessary steps to delete it. Mpclient.dll should only be present in the program directory of Microsoft Windows Defender.