Quick Answer
partmgr-sys is a legitimate Windows kernel driver. It handles partition enumeration, partition table interactions, and mounting of volumes as part of the Windows storage subsystem.
Is it a Virus?
✔ NO - Safe
Must be in C:\Windows\System32\drivers\partmgr.sys
Warning
Kernel driver operating normally
Partmgr.sys is loaded by the Windows kernel during boot to manage partitions and volumes
Can I Disable?
✔ NO
partmgr-sys is an essential Windows kernel driver; disabling it can prevent system boot or disk access.
What is partmgr-sys?
partmgr-sys is the Windows Partition Manager System Driver responsible for discovering, enumerating, and managing disk partitions. It runs in kernel mode and coordinates with the storage stack to mount and access volumes, update partition tables, and respond to partition changes initiated by the OS or disk utilities.
This driver interacts with the storage stack to read MBR/GPT tables, mount volumes, and apply partition changes. Operating in kernel mode, it ensures secure, synchronized access to disks and coordinates with Disk Management and other storage components.
Quick Fact: partmgr-sys is loaded early in the boot process to ensure partitions and volumes are available as soon as the system starts.
Types of PartMgr Processes
- Kernel Driver Service: Core driver responsible for partition management in the Windows storage stack
- Partition Table Access: Reads and validates MBR/GPT structures for disks
- Volume Mount Handler: Coordinates mounting of newly detected or resized volumes
- Partition Change Listener: Monitors partition changes from Disk Management and utilities
- Disk Health Monitor Interface: Interacts with storage diagnostics and event notifications
- Background Maintenance: Keeps metadata synchronized and handles background checks of disks
Is partmgr-sys Safe?
Yes, partmgr-sys is safe when it is the legitimate Windows kernel driver located in the System32\drivers folder and signed by Microsoft.
Is partmgr-sys a Virus or Malware?
The real partmgr-sys is not a virus. Malware may masquerade with similar names; always verify the file path and signature.
How to Tell if partmgr-sys is Legitimate or Malware
- File Location: Must be in
C:\Windows\System32\drivers\partmgr.sys. Any other location is suspicious.
- Digital Signature: Right-click
C:\Windows\System32\drivers\partmgr.sys -> Properties -> Digital Signatures. Should show "Microsoft Windows".
- Resource Usage: Normal kernel-driver usage is minimal; abnormal spikes may indicate issue but still expect small background activity.
- Behavior: The driver should be loaded by the kernel during boot and not create user-mode processes.
Red Flags: If partmgr-sys is located outside System32\drivers, lacks a valid signature, or shows persistent high-CPU or I/O during idle, run a system integrity check and malware scan.
Why Is partmgr-sys Running on My PC?
partmgr-sys runs as part of the Windows storage stack to manage partitions, discover disks during boot, and respond to changes from Disk Management and mounted volumes.
Reasons it's running:
- System Boot and Initialization: PartMgr.sys loads at boot to populate partition data and mount system volumes.
- Disk Management Operations: When you modify partitions (resize, create, delete) via Disk Management or diskpart, partmgr-sys runs to coordinate changes.
- Volume Mount and Access: Mounting new or changed volumes requires the driver to be active to expose to the OS.
- Dynamic Disk Changes: Hot-plugging disks or changing array configurations triggers the driver to update internal metadata.
- Background Health and Notifications: The driver participates in health checks and sends events to the OS when partition state changes.
Can I Disable or Remove partmgr-sys?
No, you should not disable partmgr-sys. It is a core Windows kernel driver required for partition management and mounting disks.
How to Stop partmgr-sys
- Do Not Stop the Driver: The driver is essential; stopping it can render Windows unbootable or disks inaccessible.
- Safe Mode Boot: If troubleshooting, boot into Safe Mode to minimize loaded drivers.
- System Restore: Use System Restore to revert to a known good configuration if you suspect driver issues.
- Windows Update: Ensure Windows is up to date to fix driver compatibility issues.
- Hardware Diagnostics: Run manufacturer diagnostics on disks to rule out hardware faults that could involve partition tools.
How to Repair or Restore Windows Driver Stack (partmgr-sys)
- ✔ Run sfc /scannow from an elevated Command Prompt
- ✔ Run DISM /Online /Cleanup-Image /RestoreHealth
- ✔ Run Windows Update to apply latest fixes
- ✔ Consider an in-place upgrade/repair install if issues persist
Common Problems: Partition Manager Driver Issues
If partmgr-sys causes system slowdowns, errors, or unexpected behavior, use these checks and fixes focused on partition management tasks.
Common Causes & Solutions
- Disk health problems or bad sectors: Run chkdsk and manufacturer diagnostics; check SMART data and replace failing disks.
- Partition table corruption: Back up data and repair with Disk Management or third-party tools; avoid risky edits.
- Outdated Windows or driver mismatch: Run Windows Update and optional updates; reboot to apply latest patch levels.
- High I/O from background partition tasks: Limit background indexing; disable unnecessary services related to disks; schedule heavy tasks for off-hours.
- Third-party partition tools conflict: Uninstall conflicting tools; rely on Windows Disk Management for partitioning.
- Driver signature or integrity issue: Run sfc/dism; verify signatures with Get-AuthenticodeSignature and replace corrupted files.
Quick Fixes:
1. Run chkdsk C: /f /r to check the system drive
2. Open Disk Management and verify partitions
3. Update Windows and reboot
4. Run sfc /scannow and DISM commands
5. Scan for malware and verify signatures
Frequently Asked Questions
What is partmgr-sys?
partmgr-sys is the Windows Partition Manager System Driver (partmgr.sys). It runs in kernel mode to manage partitions and mount disks as part of Windows storage.
Is partmgr-sys safe?
Yes, when it is the legitimate Microsoft-signed driver located in C:\Windows\System32\drivers and verified as partmgr.sys.
Can I disable partmgr-sys?
No. It is a core driver required for OS boot and disk access. Disabling it can prevent Windows from loading correctly.
How can I verify partmgr-sys is legitimate?
Check file location (C:\Windows\System32\drivers\partmgr.sys), verify the digital signature from Microsoft, and confirm the signature via PowerShell: Get-AuthenticodeSignature C:\Windows\System32\drivers\partmgr.sys.
What should I do if partmgr-sys causes a BSOD?
Boot to Safe Mode, run system repair commands, check for disk issues, update Windows, and consider an in-place repair install if the problem persists.
Why do partitions sometimes appear corrupted after a disk change?
Partition metadata can be affected during disk replacement or re-partitioning. Use Disk Management or backup-safe tools to repair; avoid heavy edits without backups.