What is mhk?

Mhk.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 mhk.sys is a Windows system file or if it belongs to an application that you can trust.

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

Mhk.sys file information

The process known as BestCrypt Keyboard watcher belongs to software Jetico® BestCrypt™ Encryption System for Windows (version 95/98/ME/NT/2000/XP) by Jetico (

Description: Mhk.sys is not essential for the Windows OS and causes relatively few problems. Mhk.sys is located in the C:\Windows\System32\drivers folder. Known file sizes on Windows 10/8/7/XP are 6,272 bytes (50% of all occurrences), 16,232 bytes, 7,936 bytes or 6,240 bytes. 
The driver can be started or stopped from Services in the Control Panel or by other programs. The program has no visible window. Mhk.sys is a keyboard driver, can record inputs. The service has no detailed description. The file is not a Windows core file. mhk.sys appears to be a compressed file. Therefore the technical security rating is 63% dangerous, however you should also read the user reviews.

Recommended: Identify mhk.sys related errors

Important: Some malware disguises itself as mhk.sys, particularly when not located in the C:\Windows\System32\drivers folder. Therefore, you should check the mhk.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.


User Comments

Belongs to Jetico(R) BestCrypt(TM) Encryption System
Nimmt lediglich Zeicheneingaben für die Verschlüsselung von Dateien auf.
    (further information)
None of the above is correct. I've got Bestcrypt installed myself. Its a program that scrambles keyboard input upon passwordfields. This means that if you're entering your password in the password field to mount a secret partition that you've made with Bestcrypt, programs or hardware keyloggers cannot eavesdrop on it. Kaspersky thinks its a keylogger, but it scrambles the input. It has an option in Bestcrypt itself to turn it off, and it will not protect your passwords anymore that you fill in. This is a standard file if you have the option enabled in Bestcrypt. Its NOT an essention MS file.
Part of BestCrypt encryption system. Checks that keyboard loggers are not present
  jlc   (further information)
Security program for BestCrypt software that detects keyloggers
  Endy   (further information)

Rating chart

Summary: Average user rating of mhk.sys: based on 9 votes with 5 user comments. 8 users think mhk.sys is essential for Windows or an installed application. One user thinks it's neither essential nor dangerous.

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Best practices for resolving mhk issues

A clean and tidy computer is the key requirement for avoiding problems with mhk. This means running a scan for malware, cleaning your hard drive using 1cleanmgr and 2sfc /scannow, 3uninstalling programs that you no longer need, checking for Autostart programs (using 4msconfig) and enabling Windows' 5Automatic 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 6resmon 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 7DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the mhk.sys process on your computer, the following programs have proven to be helpful: ASecurity 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. BMalwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

mhk.sys [all]