How to Extend Operating System Partition In Virtual Machine

how to extend Operating System partition for Windows Server

In this post, we will explain step by step how to expand disk capacity to extend Operating System partition for Windows Server 2016/2012 that hosted on a Virtual Machine.

I have a SharePoint virtual machine build by VMware, I have noticed that the operating system drive size is growing fast due to SharePoint Log files and SharePoint_Config log, so I have deleted the old log files and created a log backup maintenance plan for SharePoint_Config Transaction log file to truncate the log file, but it seems I still need to Extend Operating System Partition capacity.

Expand disk capacity VMware

Before you decide to extend the in Virtual Machine Hard Disk Capacity, you should first ensure that you have available free space on the Host Server drive.


  • Shutdown the running Virtual Machine.
  • Open Vmware Workstation > browse to locate VM path
  • From the left side > select edit virtual machine settings.
Edit Virtual Machine Settings
  • Below Hardware tab > Hard Disk > Click on Expand.
Expand disk capacity Vmware
  • Set the Max Disk Size (GB) > Click on Expand button.
How to Extend Operating System Partition Inside VMware

Great, you have provided new unallocated space for your virtual machine that will be used to Extend Operating System Partition

How to Extend Operating System Partition for Windows Server?

In this section, we will show How to Extend Operating System Partition for Windows Server Virtual Machine using Disk Management.


  • Power on this virtual machine.
  • Open Server Manager > Manage > Computer Management.
Computer Management.png
  • From the left side > below storage > select Disk Management.
Computer Management Disk Management
disk management extend Volume

Actually, This issue usually occurs if there is no unallocated space beside the drive that you would like to extend, and to fix this issue you should check Windows Extend Volume Greyed Out.

After applying the mentioned steps at Windows Extend Volume Greyed Out, you will note that the Extend Volume option is enabled and you can now extend the Operating System drive because you have provided unallocated space beside it as shown below:

free space beside OS
  • Now, right-click on the operating system drive, select “Extend Volume” that should be enabled now.
free space beside OS extend volume
  • The Extend volume wizard should be started > Next.
Extend Voulme Wizard.PNG
  • By default, all free space will be set,  you can change the amount of space based on your requirement.
Set Space as required.PNG
  • Click finish to close the Extend Volume wizard.
Extend Voulme Wizard completed
  • Restart the virtual machine to make sure that everything is working properly.
  • The operating system Volume should be extended successfully now.

Note: When you restart the virtual machine, you may face a windows boot problem or windows failed to start. In this case, you should follow the mentioned instructions at Windows failed to start: The Boot Configuration Data for your PC is missing or contains errors to fix this issue.


In conclusion, we have learned how to expand disk capacity in VMware by editing the virtual machine settings and provide unallocated disk space, also, we have explained how to extend operating system partition using Disk management for Windows Server 2016 and 2012.

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