Last updated on August 26th, 2020
This tutorial contains instructions to resolve the VirtualBox Error 0x80004005, when you try to start a Windows 8.1 or a Windows 10 virtual machine:” Duplicate config values ‘/CPUM/CMPXCHG16B’ and ‘/CPUM/IsaExts/CMPXCHG16B – please remove the former!'”.
After updating Oracle VM VirtualBox to version 6.0 the following error may appear when trying to start a Windows 10 or 8.1 VM machine:
“Failed to open a session for the virtual machine
Duplicate config values ‘/CPUM/CMPXCHG16B’ and ‘/CPUM/IsaExts/CMPXCHG16B’ – please remove the former! (VERR_DUPLICATE).
Component: ConsoleWrap
Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed}”
How to FIX: Duplicate config values ‘/CPUM/CMPXCHG16B’ and ‘/CPUM/IsaExts/CMPXCHG16B’ in VirtualBox.
The error “Duplicate config values ‘/CPUM/CMPXCHG16B’..”, occurs because the “CMPXCHG16B” CPU instruction is enabled on both the “VirtualBox.xml” file (C:UsersUsername.VirtualBoxVirtualBox.xml), and on Virtual Machine’s .vbox file.
To resolve the problem, follow the instructions below to remove the following line from the above locations:
1. Close VirtualBox Manager
2. Open Command Prompt as Administrator.
3. Type the following command:
- cd Program FilesOracleVirtualBox
4. Then give the below command to list the VM Machines.
- VBoxManage.exe list vms
5. From the output of the above command, notice the name of the VBOX machine, where you receive the error 0x80004005.
e.g At this example, the VM machine with the “0x80004005” error, is the “Windows8.1_x64_Pro”.
6. Then type the following command, but replace the “VM Name” value, with the name of the VBOX machine that you face the error 0x80004005, and press Enter:*
- VBoxManage.exe setextradata “VM Name” VBoxInternal/CPUM/CMPXCHG16B
* Note: The above command will disable the “CMPXCHG16B” instruction on the selected VM machine, by removing the line “
e.g. At this example the command will be:
- VBoxManage.exe setextradata “Windows8.1_x64_Pro” VBoxInternal/CPUM/CMPXCHG16B
7. Now, try to start the VM machine that has the problem. If you receive the same error, then close the VirtualBox Manager and give the following command (as admin): *
- VBoxManage.exe setextradata global VBoxInternal/CPUM/CMPXCHG16B
* Note: The above command will disable the “CMPXCHG16B” instruction globally (on all VM’s), by removing the line “
That’s it! Let me know if this guide has helped you by leaving your comment about your experience. Please like and share this guide to help others.
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