Generally ,Virtual Box displays the “E_FAIL (0x80004005)” error code when it can’t open a virtual machine session. The error could be due to problems with the VirtualBox app, configuration files, or hardware-related issues. Check the following solutions to fix this issue : Many times this error resolved by just by installing virtual box latest version. so goto virtual box website and download the Windows hosts VirtualBox setup file. You can also update VirtualBox directly within the app. Open the VirtualBox Manager app, select File on the menu bar, and select Check for Updates . Select the provided link to download the executable (.exe) file of the latest version of VirtualBox.

Hyper-V is a Windows feature that lets your computer run multiple operating systems as virtual machines. You may be unable to start or open virtual machines in VirtualBox if Hyper-V is experiencing a glitch. Restarting Hyper-V in Windows can fix this issue. follow the below steps to fix this issue. - Open the Start menu, type cmd in the search bar, and select Run as administrator below the Command Prompt. - Paste bcdedit /set hypervisorlaunchtype off in the Command Prompt and press Enter . - Open Command Prompt with administrative privileges and run the command below to re-enable Hyper-V. bcdedit /set hypervisorlaunchtype auto. bcdedit /set hypervisorlaunchtype auto. - Restart your computer again when you get a message on  Command Prompt as  “The operation completed successfully”.  Now try opening the virtual machine. Restart your computer again when you get a message on  Command Prompt as  “The operation completed successfully”.  Now try opening the virtual machine. bcdedit /set hypervisorlaunchtype auto. Restart your computer again when you get a message on  Command Prompt as  “The operation completed successfully”.  Now try opening the virtual machine.

if you cannot restore a session, discard the saved state and reopen the virtual machine. Discarding a machine’s saved state has the same effect as shutting it down. Open VirtualBox, right-click the virtual machine, select Discard Saved State (or press Ctrl + J ), and restart the session. Terminating VirtualBox without closing your virtual machine can disrupt the file conversion process. That may cause the “Result Code: E_FAIL (0x80004005)” error the next time you try to start the virtual machine. Open  VirtualBox  folder in your system  and check if there’s a .vbox file for your virtual machine. If you only find temporary ( .vbox-tmp ) and backup ( .vbox-prev ) files in the folder, you probably force-closed VirtualBox while running a virtual machine. Renaming the backup file can fix the problem and get your virtual machine running again. Close the VirtualBox Manager application and follow the steps mentioned below : - Open the VirtualBox VMs folder, select Machines , and double-click the virtual machine’s folder. - Copy or backup both files (.vbox-tmp and .vbox-prev) somewhere on your computer. Change the file extension of the temporary file from .vbox-prev to .vbox . Copy or backup both files (.vbox-tmp and .vbox-prev) somewhere on your computer. Change the file extension of the temporary file from .vbox-prev to .vbox . - Select YES on the warning prompt and open the virtual machine in VirtualBox. - Close VirtualBox and change the .vbox file back to .vbox-prev if the error persists. Afterward, rename the .vbox-temp file to .vbox and check if VirtualBox now runs the virtual machine. Close VirtualBox and change the .vbox file back to .vbox-prev if the error persists. Afterward, rename the .vbox-temp file to .vbox and check if VirtualBox now runs the virtual machine. - Please Note : Older VirtualBox versions (v3.2 and older) stores virtual machines configuration files in .xml format—not .vbox . If you find files with this extension in your virtual machine folder, rename them following the above steps. That means you’ll change files in .xml-prev or .xml-tmp format to .xml .

Copy or backup both files (.vbox-tmp and .vbox-prev) somewhere on your computer. Change the file extension of the temporary file from .vbox-prev to .vbox . Close VirtualBox and change the .vbox file back to .vbox-prev if the error persists. Afterward, rename the .vbox-temp file to .vbox and check if VirtualBox now runs the virtual machine. In your System , You must have hardware or CPU virtualization enabled to run virtual machines. If VirtualBox get the “AMD-v” or “VT-x” keywords in the error details, it means your PC’s hardware virtualization is likely disabled. Follow the  below steps to verify your computer’s hardware virtualization status. - Go to Settings > System > Recovery > Advanced startup and select Restart now . - In Windows 10, head to Settings > Updates & Security > Recovery and select Restart now in the “Advanced startup” section. In Windows 10, head to Settings > Updates & Security > Recovery and select Restart now in the “Advanced startup” section. - Go to Troubleshoot .> Advanced options .> UEFI Firmware Settings and select Restart to boot into your PC’s UEFI or BIOS settings. - Go the Configuration section on HP computers and keep Virtualization Technology enabled. - Now , “Exit” the section, select Exit Saving Changes , and select Yes to boot into Windows. - Now VirtualBox should run the virtual machine after enabling virtualization in your PC’s BIOS/UEFI settings. Now VirtualBox should run the virtual machine after enabling virtualization in your PC’s BIOS/UEFI settings. In Windows 10, head to Settings > Updates & Security > Recovery and select Restart now in the “Advanced startup” section.

Now VirtualBox should run the virtual machine after enabling virtualization in your PC’s BIOS/UEFI settings. If none of the troubleshooting tricks resolve the problem, then uninstall the virtual box – Reboot your computer – install latest virtualbox version. Follow the steps to uninstall virtual box : - Type virtualbox in the Start menu search, select Uninstall below the Oracle VM VirtualBox app and follow the uninstallation prompt. Reinstalling VirtualBox fixed the problem for some Windows users