What is mountmgr?

The genuine mountmgr.sys file is a software component of Microsoft Windows Operating System by Microsoft.
Mount Manager is a critical system file for Windows. During the boot process it mounts drives or drive partitions necessary for computer functionality. If this process fails, it will result in hard drive read/write errors and can be fatal to the OS.

MountMgr stands for Mount Manager

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

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

Mountmgr.sys file information

The process known as Mount Manager or Mount Point Manager belongs to software Microsoft Windows Operating System or Operativsystemet Microsoft Windows by Microsoft (

Description: The original mountmgr.sys is an important part of Windows and rarely causes problems. The file mountmgr.sys is located in the C:\Windows\System32\drivers folder. Known file sizes on Windows 10/8/7/XP are 42,368 bytes (80% of all occurrences), 78,784 bytes or 78,568 bytes. 
The driver can be started or stopped from Services in the Control Panel or by other programs. It is a Windows core system file. The program is not visible. The service has no detailed description. Mountmgr.sys is a trustworthy file from Microsoft. mountmgr.sys appears to be a compressed file. Therefore the technical security rating is 0% dangerous, however you should also read the user reviews.

Uninstalling this variant: If problems with Microsoft Windows occur, you can do the following:

Recommended: Identify mountmgr.sys related errors

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

i know only this i agree and understand with what you are saying but what about a clean install? likei blew the drive right away and im still getting the error after changing the HD 4 times and rom drives bios settings and so on can you help please.
It deals with file volume management. It allocates and deallocates drive letters for all devices and some versions fail to deallocate drive letters on stopping and disconnecting a device.
  Chris Thomas  
It's also used in Windows Vista & very important (if you delete this, your computer will refuse to start up!(repair? boot from cd)
  Stephane C  
getting a copy of MountMgr.sys
After a PC crash, I got a new HD, meeting all specs but my disk says mountmgr.sys is corrupt. Trying to find one on line.
Very Important file for managing and supporting the system volume information.
  trysunil   (further information)

Summary: Average user rating of mountmgr.sys: based on 7 votes with 6 user comments. 7 users think mountmgr.sys is essential for Windows or an installed application. One user is not sure about it.

Do you have additional information? Help other users!

Best practices for resolving mountmgr issues

A clean and tidy computer is the key requirement for avoiding problems with mountmgr. 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 mountmgr.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

mountmgr.sys [all]