Windows VM not detecting new vCPU allocation from Cloud Director

Products

• VMware Cloud Director

Issue/Introduction

• vCPU allocation for windows VM is updated in Cloud Director.
• vCenter UI shows the correct vCPU count after the update.
• Windows Device Manager shows the correct, updated number of processors.
• Windows Task Manager displays incorrect vCPU.

Example:
The vCPU, for the Windows VM, has been increased to 24 from the Cloud Director UI.
Within the Guest OS, under Task Manager > Performance tab, the Virtual Processors still shows the count as 12.

• Issue persists even after rebooting the VM.

Environment

VMware Cloud Director 10.x

Cause

This issue occurs when the "Number of processors" setting within the Microsoft System Configuration (msconfig) utility in the Guest OS is enabled and set to a value different than the actual vCPU allocation. This setting restricts the number of CPU cores that Windows can utilize.

Resolution

To resolve this issue, perform the following steps within the affected Windows VM:

1. Open msconfig:
• Press Windows Key + R to open the Run dialog.
• Type msconfig and press Enter.
2. Navigate to Boot Advanced Options:
• In the System Configuration window, go to the Boot tab.
• Click on Advanced options.
3. Disable "Number of processors" restriction:
• Uncheck the box next to Number of processors.
  
  
4. Apply changes and Reboot:
• Click OK on the Boot Advanced Options window.
• Click Apply, then OK on the System Configuration window.
• You will be prompted to restart the computer. Click Restart.