Article ID: 124347, created on Jan 31, 2015, last review on Jun 17, 2016

  • Applies to:
  • Virtuozzo
  • Virtuozzo hypervisor


Windows is showing that hard disks inside of a Virtual machine can be ejected, even the disk containing System (C: drive):

Ejectable disk


This behavior is correct. SATA disks virtualized by Parallels Cloud Server have hotplug functionality. They can be added to the running machine as well as removed. Since disk is capable of being ejected it is recognized as eSATA drive and displayed among devices that can be safely removed.

Even though disk C: is shown among disks that can be ejected it will be impossible to eject it because it is in use. Any additional disks can be ejected only if they are not in use.

Additional Information

Sometimes you might want to hide this functionality and let system treat disk as not removable.

The way to get rid of the option to eject the virtual disk is to make Windows believe that it is not hot-pluggable. This can be achieved by modifying the corresponding device capabilities registry value. That, however, is complicated by the facts that only SYSTEM has write access to the registry key and that Windows re-writes the correct value when booting – re-enabling HotPlug. The solution is to execute a computer startup script via Group Policy. Startup scripts are run in SYSTEM context, and since the script runs every time the system is booted we can be sure the device capabilities value is always configured the way we want it to be.

To implement the solution, create a batch file with the following content and run it as a computer startup script:

:: Disable eject hard disk
:: Original value: 4
reg.exe add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\PCI\VEN_1000&DEV_0054&SUBSYS_197615AD&REV_01\4&1f16fef7&0&00A8" /v Capabilities /t REG_DWORD /d 0 /f

Note!: Replace registry path to the device Capabilities by the path present in your system

For more information you may check following resources:

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