How to fix VMware "Failed to start the virtual machine" error in Windows?

"Failed to start the virtual machine" is the last line of a VMware Workstation power-on error, not the cause itself. The line above it names what failed: most often hardware virtualization that is off in the UEFI, or Windows Hyper-V and virtualization-based security that an old Workstation cannot use. Read that line first, then pick the fix that matches it.

Facts checked on 15 October 2026. Steps written for Windows 11 (25H2 and 26H2) and Windows 10 22H2.

What "Error while powering on: Failed to start the virtual machine" means

VMware Workstation shows this dialog when it cannot start the part that runs the virtual machine. The full text is Error while powering on: Failed to start the virtual machine. The last sentence is always the same. The sentences above it change and tell you why.

Broadcom's knowledge base gives one full example. It reads: "This host supports Intel VT-x, but Intel VT-x is disabled." It then lists four checks and ends with "Failed to start the virtual machine. Module MonitorMode power on failed." A module is one part of the start process, and its name is your best clue.

Why VMware fails to start the virtual machine

Most often hardware virtualization is off. Less often Windows has turned on Hyper-V, memory integrity or another virtualization-based security feature, and an older Workstation cannot run next to it. Rarely the cause sits in one virtual machine, in a stuck VMware process or in a damaged install.

• Virtualization off in the UEFI (most often). Broadcom says VT must be on in the firmware. The setting is read only at power on, so a plain restart after the change is not enough.
• Hyper-V or VBS on Windows (often after a Windows 11 upgrade). Broadcom's documentation says traditional Workstation cannot run on a host with Hyper-V or VBS. Version 15.5.5 and later switch to the Windows Hypervisor Platform instead.
• Nested virtualization asked for (sometimes). The VM has the option to virtualize VT-x/EPT or AMD-V/RVI ticked, and the host cannot give it while Windows runs its own hypervisor.
• A .vmx line after an upgrade (sometimes). Users on Broadcom's forum report that every VM failed after an upgrade from 17.5.2 to 17.6 until they removed vmx.scoreboard.enabled from the .vmx file.
• Stuck processes, services or install files (rarely). A half-closed VMware process or a stopped VMware service can block the next start.

How to fix VMware "Failed to start the virtual machine"

Fixes 1 to 4 match the line above the message and solve most cases. Fixes 5 to 7 reset VMware itself. Fix 8 is a general Windows rollback for the few cases that remain.

Fix 1. Turn on Intel VT-x or AMD-V in the UEFI and power the PC off

10 minutesLow riskThe message says Intel VT-x or AMD-V is disabled, or names the module MonitorMode.

Broadcom's article on this exact message says the CPU supports virtualization but the firmware has it off. The setting is locked at power on, so it takes effect only after a full power off, not a restart.

1. Press Win + R, type taskmgr and press Enter. Open the Performance page and select CPU. If Virtualization says Enabled, skip to Fix 2.
2. Open Settings > System > Recovery and select Restart now next to Advanced startup. On Windows 10 it is Settings > Update & Security > Recovery.
3. Choose Troubleshoot > Advanced options > UEFI Firmware Settings > Restart.
4. Find the setting. Broadcom lists the names VT, Vanderpool Technology, Virtualization Technology, VMX and Virtual Machine Extensions. On AMD PCs it is often SVM or AMD-V.
5. Set it to Enabled. Broadcom notes it often sits on a Security screen.
6. Save the change and let the PC start, then shut it down completely with Start > Power > Shut down.
7. Turn the PC on again and power on the virtual machine.

Fix 2. Update VMware Workstation so it runs on top of Hyper-V, then reinstall it

20 minutesLow riskThe message names Hyper-V, Device or Credential Guard, or the error began after Windows 11, WSL 2 or memory integrity was turned on.

Broadcom's documentation says Workstation 15.5.5 and later start VMs through the Windows Hypervisor Platform when Hyper-V is active. It also says the installer checks Hyper-V and WHP during setup, so a reinstall after a Windows change makes it look again.

1. Open Workstation and select Help > About VMware Workstation. Write down the version.
2. Check the host: Broadcom asks for an Intel Sandy Bridge or AMD Bulldozer or newer CPU, and Windows 10 20H1 build 19041.264 or newer. Press Win + R, type winver and press Enter to read your build.
3. Press Win + R, type optionalfeatures and press Enter.
4. If Hyper-V or Virtual Machine Platform is ticked, tick Windows Hypervisor Platform too, select OK and restart.
5. Download the newest Workstation installer from Broadcom's support portal and run it. Choose Repair if it offers that, or install over the old version.
6. Restart the PC and power on the virtual machine.

Fix 3. Turn off nested virtualization in the settings of the virtual machine

3 minutesLow riskThe dialog names the module HV or nested virtualization, or only one virtual machine fails while others start.

A VM with virtualized VT-x/EPT or AMD-V/RVI wants to run its own hypervisor inside. Broadcom has a knowledge base article on the message "Virtualized Intel VT-x/EPT is not supported on this platform", which ties it to Windows virtualization-based security on the host.

1. Shut the virtual machine down if it is suspended. A suspended VM keeps its old processor settings.
2. Select the VM in the Library and choose VM > Settings.
3. On the Hardware tab select Processors.
4. Under Virtualization engine, clear Virtualize Intel VT-x/EPT or AMD-V/RVI.
5. Select OK and power on the virtual machine.

You lose only the ability to run Hyper-V, WSL 2, Docker or another hypervisor inside this guest. Windows and Linux guests themselves start normally without it.

Fix 4. Remove the scoreboard line from the .vmx file after a Workstation upgrade

5 minutesRead the warningEvery virtual machine fails right after you upgraded Workstation, and the dialog shows no other line.

Users on Broadcom's forum report that after an upgrade from 17.5.2 to 17.6 all VMs failed with this message until they deleted the vmx.scoreboard.enabled line. Another user fixed a cloned VM by renaming its scoreboard file entry to the new VM name.

1. Close VMware Workstation completely.
2. Open the folder of the virtual machine. If you do not know where it is, search File Explorer for *.vmx.
3. Copy the file <name>.vmx to the desktop as a backup.
4. Right-click the original, select Open with > Notepad.
5. Press Ctrl + F and search for scoreboard.
6. Delete the line vmx.scoreboard.enabled = "TRUE" if it is there. On a cloned VM, make the file name in a scoreboard line match the new VM name instead.
7. Save the file and power on the VM.

Fix 5. Close every VMware process and start Workstation as administrator

5 minutesLow riskThe error came after a crash, a sleep or a suspended VM, and no extra line is shown.

A VMware process left from the last session can still hold the virtual machine. Ending them all and starting once with full rights lets Workstation open the VM files again.

1. Close Workstation.
2. Press Ctrl + Shift + Esc to open Task Manager.
3. Type vmware in the search box at the top.
4. Right-click each VMware Workstation or VMware Player entry and select End task. Leave the NAT, DHCP, USB Arbitration and Authorization services running.
5. Press Win, type vmware, and select Run as administrator, then Yes.
6. Power on the virtual machine.

More about both tools: Close a frozen app (Task Manager, Force Quit) and How to run a program as administrator or in compatibility mode

Fix 6. Start the VMware Authorization Service and the other VMware services

5 minutesNo riskWorkstation says the VMware Authorization Service failed to start, or VMs start only as administrator.

Workstation needs its own Windows services to power on a VM for a normal user. When the authorization service is stopped or set to Disabled, the start fails before the guest runs.

1. Press Win + R, type services.msc and press Enter.
2. Find VMware Authorization Service in the list.
3. Double-click it and set Startup type to Automatic.
4. Select Start, then OK.
5. Do the same for the other services whose names start with VMware if they are stopped.
6. Power on the virtual machine.

Step by step with pictures: Check and restart Windows services

Fix 7. Repair or reinstall VMware Workstation

20 minutesLow riskVMware services are missing or will not start, or every VM fails and Fixes 1 to 6 did not help.

The installer puts back the VMware drivers and services and runs its Hyper-V check again. Your virtual machines are separate folders and stay on the disk when Workstation is removed.

1. Download the newest Workstation installer from Broadcom's support portal.
2. Run it and choose Repair if it offers that. Restart and test.
3. If the error stays, open Settings > Apps > Installed apps, select the three dots next to VMware Workstation and select Uninstall.
4. Restart the PC.
5. Run the new installer and restart again when it asks.
6. Open your VM with File > Open and select its .vmx file.

On Windows 10 the list sits in a different place in Settings: Uninstall a program or app in Windows

Fix 8. Roll Windows back with System Restore

30 minutesLow riskThe VM worked until a Windows update, a driver or a security tool changed something, and you have a restore point from before.

If a Windows change turned on a feature that blocks Workstation and you cannot find which one, a restore point from before brings back the old drivers and settings. Your own files are not changed.

1. Press Win + R, type rstrui and press Enter.
2. Choose a restore point from before the error began and follow the wizard.

Full steps and what to do if no restore point exists: Undo recent changes with System Restore

If VMware still says Error while powering on: read vmware.log

The dialog shows only the end of the story. Every power-on attempt writes vmware.log in the folder of the virtual machine, and its last lines name the module that failed. That is the line people on Broadcom's forum ask for first.

1. Try to power on the VM once more and close the dialog.
2. Open the VM's folder. Search File Explorer for *.vmx if you do not know where it is.
3. Open vmware.log in Notepad and press Ctrl + End.
4. Read upward until you find a line with power on failed, and note the module name and the lines just before it.
5. Compare it with the table under "What the error means" and go to that fix.

• What to send for help: vmware.log, the Workstation version from Help > About, your Windows build from winver, and whether Hyper-V or memory integrity is on.
• Error 18 or another number: we could not find a Broadcom page that explains it. The log line next to it is what tells you the cause.
• When it is hardware: Task Manager shows no Virtualization line, or the UEFI has no VT option. Broadcom says some PCs ship VT-capable but without a firmware switch. Then only a firmware update from the PC maker can help.
• A work or school PC: an administrator may force Device Guard or Credential Guard on by policy. Fix 2 still works, but you cannot turn those off yourself.

How to keep VMware from failing to start the virtual machine again

Windows 10 left Microsoft's support on 14 October 2025. Broadcom's Hyper-V mode still lists Windows 10 build 19041.264 or newer, but Windows 11 is the safer host now.

Frequently asked questions

What does "Failed to start the virtual machine" mean in VMware?

It means VMware Workstation could not start the part that runs your virtual machine, so the guest system never began to boot. The sentence is the same for many causes. The line above it in the dialog, or the end of vmware.log, names the module that failed. Broadcom's example says Intel VT-x is disabled and names the module MonitorMode. Other common lines mention Hyper-V, Device or Credential Guard, or the module HV. Match that line with the table near the top of this page.

Why does every VMware virtual machine fail after an upgrade to Windows 11?

Windows 11 often turns on virtualization-based security and memory integrity, which run on Hyper-V. Broadcom says traditional Workstation cannot run on such a host. Workstation 15.5.5 and later use the Windows Hypervisor Platform instead, and the installer checks this during setup. So install the newest Workstation or repair the one you have after the upgrade (Fix 2). Your CPU must be Intel Sandy Bridge or AMD Bulldozer or newer for this mode.

Can VMware Workstation run with Hyper-V, WSL 2 or memory integrity turned on?

Yes, from Workstation 15.5.5 on. Broadcom's documentation says that when Hyper-V or the Windows Hypervisor Platform is active, Workstation launches VMs through that platform. When they are off, it uses VMware's own hypervisor. The host needs Windows 10 20H1 build 19041.264 or newer. Broadcom lists some limits of this mode, so a VM may run slower than before. Nested virtualization inside the guest is the usual thing that stops working.

Should I turn off memory integrity to fix VMware?

No, not as a lasting fix. Memory integrity blocks malicious drivers from the Windows kernel, and a current Workstation runs with it on. Many older guides advise turning it off because they were written for Workstation versions before 15.5.5. Update and repair Workstation instead (Fix 2). If you must test whether it is the cause, turn it back on right after the test.

What is VMware "failed to start the virtual machine" error 18?

We could not find a Broadcom page that defines an error 18 for this message, so we will not guess. A number in the dialog is less useful than the module name. Open vmware.log in the folder of the VM, go to the end and read upward to the line that says power on failed. The module named there tells you which fix on this page to use. Send that part of the log if you ask for help.

Why does VMware say the Authorization Service failed to start?

The VMware Authorization Service lets normal users power on virtual machines. If it is stopped, set to Disabled or damaged, Workstation cannot start a VM unless it runs as administrator. Open services.msc, set the service to Automatic and select Start (Fix 6). If it refuses to start or is missing from the list, repair or reinstall Workstation (Fix 7). Your VM folders are not touched by a reinstall.

My virtual machine powers on but fails to boot. Is that the same error?

No. Failed to start the virtual machine appears before the guest runs at all, in a VMware dialog. If you see the VMware logo, a boot menu, or a message from Windows or Linux inside the VM window, the VM did start. Then the problem is in the guest: a missing installation disc or ISO, a wrong boot order or a damaged guest system. Those need different fixes than the ones on this page.

Is "terminated unexpectedly during startup with exit code 1 (0x1)" the same problem?

That message comes from VirtualBox, not VMware, and "An error occurred while attempting to start the selected virtual machine" comes from Hyper-V Manager. The root causes overlap, though. Virtualization turned off in the UEFI (Fix 1) stops every hypervisor. Hyper-V and virtualization-based security also affect VirtualBox. For VirtualBox specific steps, use its own log and documentation.

Will I lose my virtual machines when I fix this error?

No, none of the fixes here deletes a VM. The error happens before the guest starts, and the virtual disks stay in the VM folder. A reinstall of Workstation leaves those folders in place, and File > Open brings them back. The one edit with some risk is the .vmx change in Fix 4, so copy that file first. Also shut down suspended VMs before a Workstation upgrade.