How to fix Media Creation Tool error 0x8007043C - 0x90018 in Windows?

Error 0x8007043C - 0x90018 means the Media Creation Tool asked Windows to start a service and Windows refused. The first code is Windows error 1084, "This service cannot be started in Safe Mode." Restart Windows normally and run the tool again; if the PC only works in Safe Mode, make the USB drive on another PC.

Facts checked on 16 October 2026. Steps written for Windows 11 25H2 and 26H2, and Windows 10 22H2, with the Windows 11 and Windows 10 Media Creation Tool.

What Media Creation Tool error 0x8007043C - 0x90018 means

The Media Creation Tool shows its error in a window titled Windows 11 Setup or Windows 10 Setup. The text reads: There was a problem running this tool. We're not sure what happened, but we're unable to run this tool on your PC. Below it you see Error code: 0x8007043C - 0x90018.

If your first code is 0x80070006 instead, read our guide to Media Creation Tool error 0x80070006 - 0x90018. That one is about an invalid handle, not about services.

Why the Media Creation Tool fails with 0x8007043C - 0x90018

Microsoft does not publish a cause for this pair. The ranking below follows the meaning of error 1084 and what the tool needs: normal Windows with its background services, an internet connection and, for a USB drive, a blank drive of 8 GB or more. Each cause points to a fix.

How to fix Media Creation Tool error 0x8007043C - 0x90018

Fix 1 solves the error for most readers, because the tool cannot run in Safe Mode. Fix 2 and Fix 3 get Windows to you without running the tool on this PC. Fix 4 to Fix 8 are for a PC in normal mode where a service or another program still blocks the tool.

Fix 1. Leave Safe Mode and run the Media Creation Tool in normal Windows

5 minutesNo riskThe PC runs in Safe Mode now, or it starts in Safe Mode every time because Safe boot is ticked in System Configuration.

Error 1084 is Windows saying a service cannot start in Safe Mode. In normal Windows the services the tool needs can start, so the same tool passes the step where it failed.

1. Leave Safe Mode. When you are done, restart the PC normally. Windows starts in normal mode again.
2. If it keeps starting in Safe Mode. Press Windows key + R, type msconfig and press Enter. On the Boot tab, clear Safe boot, select OK and restart.

   

These steps were written for Windows 11 24H2 and later; Windows 10 22H2. The full page with the other versions and what each result means: Start Windows or a Mac in Safe Mode

1. After the restart, check that the words Safe Mode are gone from the corners of the screen.
2. Right-click MediaCreationTool.exe and select Run as administrator. Select Yes in User Account Control.
3. Accept the licence terms and choose Create installation media, or Upgrade this PC now in the Windows 10 tool.

Fix 2. Make the USB drive on another PC when Windows only works in Safe Mode

30 minutes, plus the downloadRead the warningNormal Windows crashes or freezes, so you can only use the PC in Safe Mode, as in the reader's question.

The tool must run in normal Windows, but it does not have to run on the broken PC. A USB drive made on any working Windows PC installs Windows on yours.

1. On a working Windows PC, download the Media Creation Tool from Microsoft's software download page for Windows 11.
2. Plug in one blank USB flash drive with at least 8 GB, and unplug other USB drives.
3. Right-click the tool and select Run as administrator, then choose USB flash drive and pick your drive.
4. Wait for Your USB flash drive is ready, then plug the drive into your PC.
5. Start your PC from the USB drive with the boot menu key of your PC, often F12, F11, F8 or Esc.
6. In Windows Setup, choose your language and follow the steps to install Windows.

If you would rather repair than reinstall, the same USB drive has a Repair your computer link on the first Setup screen. It opens the recovery tools: Run Startup Repair.

Fix 3. Skip the tool: mount the Windows 11 ISO and run setup.exe

10 minutes, plus the downloadRead the warningNormal Windows works on this PC, and you want to reinstall, repair or upgrade the Windows you are on.

The ISO is a ready image of the same Windows files. Your browser downloads it and Windows opens it as a drive, so the tool's own start-up, where the service error comes from, is never run.

1. Make sure Windows is in normal mode, not Safe Mode (Fix 1).
2. Open Microsoft's Download Windows 11 page and go to Download Windows 11 Disk Image (ISO).
3. Select Windows 11 in Select Download, select Download, pick your language and download the 64-bit ISO.
4. Open Downloads in File Explorer, right-click the ISO file and select Mount.
5. Open the new drive and double-click setup.exe. Select Yes in User Account Control.
6. Follow Setup and choose what to keep: Keep personal files and apps, Keep personal files only or Nothing.

Step by step, with the keep options explained: Reinstall Windows without losing files

Fix 4. Set the services the tool needs back from Disabled

5 minutesLow riskWindows runs normally, but the error stays, and you ran a tuning, privacy or debloat tool, or Windows Update fails too.

Error 1084 is a refusal to start a service. If a tool set Background Intelligent Transfer Service or Windows Update to Disabled, the Media Creation Tool cannot start them, even in normal mode.

1. Open Services. Press Windows+R, type the command below and press Enter. You can also type Services in the search box on the taskbar and open the app.

   services.msc

2. Find the service. The list is sorted by Name. Click any row and type the first letter of the service to jump to it. Check the Status column (Running or empty) and the Startup Type column.

   

3. Restart the service. Right-click the service and select Restart. If the service is not running, select Start instead. Wait until the progress window closes.

   

4. Open its properties to change the startup type. Only if your guide says so: double-click the service. The General tab shows the Service name (used in commands), the Startup type and the Service status.

   

5. Set the startup type and apply. Choose the type from the Startup type list (Automatic, Automatic (Delayed Start), Manual or Disabled), select Apply, then Start if the service should run now, and OK.

These steps were written for Windows 11 and Windows 10 (the steps are the same). The full page with the other versions and what each result means: Check and restart Windows services

• Check Background Intelligent Transfer Service and Windows Update first.
• If one shows Disabled, set it to Manual, select Apply, then Start.
• If a tuning or privacy tool changed them, undo its service changes there, or it may disable them again at the next start.

Fix 5. Reset the Windows Update components

10 minutesLow riskThe services start but the tool still fails, or Windows Update shows errors as well.

The tool uses the same download services as Windows Update. A reset stops them, renames their caches and starts them again, which clears a damaged state that keeps them from starting.

1. Open Command Prompt as administrator. Type cmd in the search box, right-click Command Prompt and select Run as administrator. Select Yes when Windows asks for permission.
2. Stop the update services. Type the commands below and press Enter after each one. If Windows says that other services depend on Cryptographic Services, it stops them too. A message that a service is not started is fine.

   net stop wuauserv
   net stop bits
   net stop cryptsvc

   

3. Delete the download queue files. This clears the list of downloads that the Background Intelligent Transfer Service keeps. If Windows says it cannot find the files, continue.

   del "%ALLUSERSPROFILE%\Application Data\Microsoft\Network\Downloader\qmgr*.dat"

4. Rename the update cache folders. Renaming keeps a copy in case you need it; Windows creates new, empty folders when the services start again. If you get Access is denied, a service is still running: repeat the previous step.

   ren %systemroot%\SoftwareDistribution SoftwareDistribution.old
   ren %systemroot%\System32\catroot2 catroot2.old

   

5. Start the services again. Type the commands below and press Enter after each one. The requested service has already been started is fine: Windows started it on its own.

   net start cryptsvc
   net start bits
   net start wuauserv

   

6. Restart and check for updates. Restart the PC. Then select Start > Settings > Windows Update > Check for updates. The first check can take longer than usual because everything is downloaded again.

These steps were written for Windows 11 and Windows 10 (the steps are the same). The full page with the other versions and what each result means: Reset Windows Update components

1. Restart the PC after the reset.
2. Run the Media Creation Tool again as administrator, as in Fix 6.

Fix 6. Run a fresh copy of the Media Creation Tool as administrator

5 minutesNo riskYou need a USB drive or an ISO file, and the tool is an old download or was started by double-click.

Starting services needs administrator rights. A new copy also rules out an old version of the tool that no longer matches the current Windows download.

1. Delete every old MediaCreationTool.exe you have. Microsoft notes the name may carry a version, such as MediaCreationTool_22H2.exe.
2. Download the tool again from Microsoft's software download page for Windows 11, or for Windows 10 if you still need it.
3. Move the file to a local folder such as C:\MCT, outside OneDrive.
4. Right-click the file and select Run as administrator. Select Yes in User Account Control.

More on administrator rights: How to run a program as administrator or in compatibility mode

Fix 7. Run the tool from a clean boot, with security software paused for one test

20 minutesLow riskFix 1 to Fix 6 are done, and the PC has a non-Microsoft antivirus, backup or tuning program.

Some security and tuning programs block or stop Windows services. A clean boot starts normal Windows without them, unlike Safe Mode, so the tool's services can still start.

1. Open System Configuration. Select Search on the taskbar, type msconfig and select System Configuration from the results.
2. Hide Microsoft services. On the Services tab, select the Hide all Microsoft services check box. Only services from other companies stay in the list.

   

3. Disable the remaining services. Select Disable all, then select Apply.
4. Open Task Manager. On the Startup tab of System Configuration, select Open Task Manager.

   

5. Disable the startup apps. On the Startup apps tab in Task Manager, select each item whose status is Enabled and select Disable. Write down or take a screenshot of the items you disable: you need the list to turn them back on.

   

6. Confirm the changes. Close Task Manager. On the Startup tab of System Configuration, select OK.
7. Restart and test. Restart the PC. Windows now starts in a clean boot environment: try again the thing that failed (run the app, install the update, uninstall the program).

These steps were written for Windows 11 25H2 and 26H2. The full page with the other versions and what each result means: How to perform a clean boot in Windows

1. In the clean boot, run the Media Creation Tool as administrator.
2. If it fails again, pause your antivirus for this one attempt only: Turn off Microsoft Defender protection for a moment.
3. When the tool has finished, turn the antivirus back on and undo the clean boot as the procedure describes.

Fix 8. Repair Windows system files with DISM and SFC

20 to 40 minutesLow riskEverything above failed, or other Windows tools also show errors.

If the files behind Windows services are damaged, the services cannot start for any program. DISM and SFC restore them from Microsoft's copies.

1. Open an elevated command window. Right-click Start and select Terminal (Admin), or type cmd in the search box, right-click Command Prompt and select Run as administrator. Select Yes when Windows asks for permission.

   

2. Run DISM first. Type the command below and press Enter. DISM downloads clean copies of damaged components from Windows Update, so it can take several minutes. Wait until it says The operation completed successfully.

   DISM.exe /Online /Cleanup-Image /RestoreHealth

   

3. Run System File Checker. In the same window, type the command below and press Enter. Do not close the window until the verification reaches 100%.

   sfc /scannow

   

4. Read the result and restart. Compare the last message with the table below this guide, then restart the PC so that repaired files are loaded.

   

These steps were written for Windows 11 24H2 and 25H2. The full page with the other versions and what each result means: Run DISM and SFC to repair Windows system files

1. Restart the PC normally when both commands have finished.
2. Run the Media Creation Tool again as administrator.

If Media Creation Tool error 0x8007043C - 0x90018 is still there

When the tool fails in normal Windows, in a clean boot and after the repairs, the problem is a service on this PC that will not start. You can still get Windows another way, and Windows logs which service failed.

• What to send to Microsoft support: both codes, the Windows version you run, whether the PC was in Safe Mode, and the step where the tool stopped.
• Add the name of any service from Event Viewer that failed to start, and whether the ISO option works.
• Say which tuning, privacy or security programs are installed.

How to keep 0x8007043C - 0x90018 from coming back

Windows 10 left support on 14 October 2025. If you make media to reinstall a Windows 10 PC, check whether it can run Windows 11 first.

Frequently asked questions

What does error code 0x8007043C - 0x90018 mean?

It means the Media Creation Tool could not start a Windows service it needs. The first code, 0x8007043C, is Windows error 1084, ERROR_NOT_SAFEBOOT_SERVICE, "This service cannot be started in Safe Mode." The second code, 0x90018, is the tool's own code and appears after many first codes. Most often the PC runs in Safe Mode, where the tool cannot work. Less often a service such as Windows Update or BITS is disabled. Your PC, licence and files are not damaged by the error.

What is error 0x8007043C on its own?

0x8007043C is the general Windows error 1084: a program asked Windows to start a service that is not allowed to run in Safe Mode. The 0x8007 part says it is a Win32 error, and 43C is 1084 in hexadecimal. You can see it in the Media Creation Tool, in Windows Update and in some security programs, usually when the PC runs in Safe Mode. Restart Windows normally and try again before anything else. If you are not in Safe Mode, a disabled service is the next suspect.

Can I run the Media Creation Tool in Safe Mode?

No, not reliably, and 0x8007043C is the result. Safe Mode starts only a minimal set of drivers and services, and the tool needs services that Safe Mode does not start, so Windows refuses them. Do not count on Safe Mode with Networking either: the internet works there, but the other services stay off. Run the tool in normal Windows (Fix 1). If your PC only works in Safe Mode, run the tool on another PC and use its USB drive on yours (Fix 2).

My PC only works in Safe Mode. How do I reinstall Windows?

Make the installation USB drive on another working PC. First copy your files off this PC while it is in Safe Mode, because a clean install can delete drive C. On the other PC, run the Media Creation Tool as administrator with a blank USB drive of at least 8 GB. Then start your PC from that drive with its boot menu key and follow Windows Setup. Fix 2 has the steps. The drive can also open the repair tools if you would rather try those first.

What does 0x90018 mean in the Media Creation Tool?

0x90018 is the second half of the code, which Microsoft calls the extend code. It is the tool's own code and appears after several first codes, such as 0x80070006, 0x80070003 and 0x8007043C. Microsoft does not document its exact meaning, and we could not confirm one. That is why the first code decides the fix. With 0x8007043C it is Safe Mode or a blocked service; with 0x80070006 it is an invalid handle, covered in our separate guide.

What about error code 0x80070006 - 0x90018?

It is a different error with the same second code. 0x80070006 is Windows error 6, "The handle is invalid": the tool lost access to a file, folder or drive it had opened. Its causes are an old copy of the tool, the USB drive or leftover setup files, not Safe Mode. Our guide to Media Creation Tool error 0x80070006 - 0x90018 has the fixes in order. Using the ISO instead of the tool helps with both errors.

Can I reinstall Windows without the Media Creation Tool?

Yes. Microsoft offers the Windows 11 disk image (ISO) for direct download. In normal Windows, right-click the ISO, select Mount and run setup.exe from the new drive. Setup lets you keep your files and apps, keep only your files, or keep nothing. This repairs or reinstalls Windows on the same PC, which is what most readers who see this error want. Fix 3 has the steps. Back up your files first in every case.

Do I need a product key to use the tool or the ISO?

Not on most PCs. Microsoft says a 25-character product key might be needed, but not for digital licences. Many modern PCs have the key stored in their firmware, and Setup applies it by itself when it matches the version and edition you install. If you reinstall the same edition that was activated on this PC, Windows activates again. The error 0x8007043C - 0x90018 has nothing to do with the key or the licence.

I searched in another language. Does this page apply to me?

Yes, if your screen shows the codes 0x8007043C and 0x90018. The codes are the same in every language; only the text around them is translated. The fixes work the same on Windows in Russian, Chinese or any other language, so follow them in order, starting with leaving Safe Mode. If you searched for how to install Windows 11 in general, the ISO method in Fix 3 and the USB method in Fix 2 are the two ways Microsoft offers.