How to fix File System Error (-2018374635) in Windows?

File system error (-2018374635) appears when a built-in part of Windows, such as Settings, the Start menu, the taskbar or Notification Center, fails to start. It often begins after a Windows update and is not a disk fault. Restart the Windows shell first, then register the built-in apps again.

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

What File system error (-2018374635) means

The box has a red cross and one OK button. The title bar and the first line show the address Windows tried to open, and the second line says File system error (-2018374635). In the box below, the address is ms-wpc://appblock?cver=RS1&n=Shell%20Input%20Application&pk=InputApp_cw5n1h2txyewy, which names the Shell Input Application (the touch keyboard and input panel). Other readers see an address that starts with ms-actioncenter:, or no box at all, just a Settings window that never opens.

The words "file system" are misleading. The number is a Windows error code written as a negative decimal number. In hex, -2018374635 is 0x87B20C15. Windows prints that same hex code in the message "Unable to activate Windows Store app", when an app package fails to start. So the code says one thing: Windows asked a built-in app to start, and the start failed. We could not find a Microsoft name or description for the code itself.

If the address starts with ms-wpc://appblock, Windows was trying to show its app block page, the page that family safety settings use when an app is limited. On a child account in Microsoft Family, check the app and screen time limits in the family settings first. On an adult account, treat it like any other case and go to Fix 1. A related but different code, which follows a failed System Restore and blocks Control Panel pages, has its own guide: File system error (-2144926975).

Why File system error -2018374635 appears

The reader on Microsoft Q&A who first reported this code wrote that the taskbar and the Start button stopped working and Settings would not open, and that all they did was install a Windows update. Rank the causes like this.

How to fix File system error (-2018374635) in Windows

Fix 1 takes two minutes and clears a stuck shell. Fix 2 is the one that repairs the cause for most readers: it registers Settings and the shell apps again. Fix 3 deals with the update that started it. Fixes 4 to 7 repair Windows itself, from the smallest step to a repair install that keeps your files and apps.

Fix 1. Restart Windows Explorer and the Start and shell hosts

2 minutesNo riskThe taskbar shows no app icons, Start does not open, or the box appeared once after sleep or an update.

The taskbar, Start and Notification Center run in a few shell processes. If one of them hangs, every app it should start fails with this code. Restarting Explorer is the first step an independent advisor gives for this code on Microsoft Q&A; ending the two host processes restarts Start and the notification area too.

1. Press Ctrl + Shift + Esc to open Task Manager. Select More details if you see a short list.
2. On Processes, find Windows Explorer, select it and choose Restart task (Windows 11) or right-click it and select Restart (Windows 10).
3. Open Details. Right-click StartMenuExperienceHost.exe and select End task, then do the same for ShellExperienceHost.exe. Windows starts both again by itself.
4. Click Start, a taskbar icon and the clock to test Start, the taskbar and Notification Center.
5. If any of them still fails, restart Windows with Ctrl + Alt + Delete, the power icon and Restart.

Step by step with Windows 10 differences: Restart File Explorer

Fix 2. Register Settings and the shell apps again with PowerShell

15 minutesLow riskSettings never opens, the box names an app address, or Fix 1 helped only for a while.

Settings is the app package windows.immersivecontrolpanel, and Start and Notification Center are packages too. When an update leaves their registration broken, Windows cannot start them and returns this code. Registering them again from their own folder repairs that without removing any of your files. This is the repair the Microsoft Q&A advisor gives for this code.

1. Right-click Start and select Terminal (Admin) (Windows 11) or Windows PowerShell (Admin) (Windows 10), then select Yes.
2. If the right-click menu fails too, press Ctrl + Shift + Esc, select Run new task, type powershell, tick Create this task with administrative privileges and select OK.
3. Run the first command below. It registers Settings again.
4. Run the second command. It registers the Start menu and the shell experience host.
5. Restart Windows and open Settings with Win + I.

Register Settings again (PowerShell as administrator)

Get-AppXPackage -AllUsers -Name windows.immersivecontrolpanel | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml" -Verbose}

Register Start and the shell experience host again

Get-AppXPackage -AllUsers -Name *StartMenuExperienceHost*, *ShellExperienceHost* | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml" -Verbose}

If only one app fails, these two commands are enough. If many built-in apps fail, register all of them at once with the command in How to re-register Microsoft Store apps with PowerShell Red lines for apps that are in use are normal.

Fix 3. Finish or remove the Windows update that started it

15 to 30 minutesLow riskThe error started on the day a Windows update installed, or Windows says a restart is pending.

The first report of this code came straight after an update. An update that is half installed, or that replaced the built-in apps with a version that does not start on your PC, breaks them all at once. Finishing it, installing the next one, or removing it puts the apps back in step.

1. Restart Windows from Start > Power and choose Update and restart if it is offered. Let the update finish.
2. If Settings opens, go to Settings > Windows Update and select Check for updates. A later update may carry the fix.
3. If the error stays, open Settings > Windows Update > Update history > Uninstall updates (Windows 11) or Settings > Update & Security > View update history > Uninstall updates (Windows 10). Remove the update installed on the day the error began.
4. If Settings does not open at all, hold Shift and select Start > Power > Restart, then choose Troubleshoot > Advanced options > Uninstall Updates > Uninstall latest quality update.
5. Restart and test Settings and Start again.

Both ways, with screenshots: How to uninstall a Windows update

Fix 4. Repair Windows system files with DISM and SFC

30 minutesNo riskSeveral built-in apps fail, or Fixes 1 to 3 did not hold.

Built-in apps rely on Windows system files. If some of them are damaged, registering the apps again does not help, because they still cannot start. DISM fetches clean copies from Windows Update and SFC puts them back.

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

If the error keeps you from opening a Command Prompt, start Safe Mode first: Start Windows or a Mac in Safe Mode

Fix 5. Test Settings and Start in a new local administrator account

10 minutesLow riskFixes 1 to 4 did not help, or you want to know whether only your account is affected.

Built-in apps are registered per user. A new account gets a fresh registration of every app, so it shows at once whether the damage sits in your profile or in Windows itself.

1. Open an administrator Terminal or PowerShell window as in Fix 2.
2. Run the first command below with a name and password of your choice. It creates a local account.
3. Run the second command. It makes the new account an administrator.
4. Sign out and sign in to the new account. The first sign-in takes a minute or two.
5. Open Settings, Start and Notification Center.

Create a local administrator account (Terminal as administrator)

net user FixTest YourPassword1 /add
net localgroup administrators FixTest /add

The Settings way, step by step: Create a new user account to test a problem

Fix 6. Go back to a restore point from before the error

20 to 40 minutesRead the warningWindows has a restore point from before the error began, and Fixes 1 to 5 helped only for a while or not at all.

A restore point holds the system files, app registrations and drivers from its date. Going back to a point from before the update or change puts Settings and the shell apps back the way they worked. The Microsoft Q&A advisor gives this as the step after the app repair.

1. Press Win + R, type rstrui.exe and press Enter.
2. Select Next and tick Show more restore points.
3. Pick a point dated before the first File system error (-2018374635) box.
4. Select Scan for affected programs to see what will be removed, then Next and Finish.
5. If Windows will not stay usable, hold Shift, select Restart, and open Troubleshoot > Advanced options > System Restore instead.

Full steps with screenshots: Undo recent changes with System Restore

Fix 7. Repair Windows and keep your files and apps

60 to 90 minutesLow riskFixes 1 to 6 did not help, or many built-in parts of Windows still fail.

A repair install puts a complete, current copy of Windows and its built-in apps over the damaged one, while it keeps your files, settings and installed apps. It replaces every built-in app package at once, which is what this error needs when the smaller repairs do not hold.

1. Back up your important files first: Back up your files (Windows Backup, File History, Time Machine)
2. On Windows 11, open Settings > System > Recovery and select Reinstall now next to Fix problems using Windows Update.
3. If Settings does not open, download the Windows installation media from Microsoft, open it and run setup.exe.
4. Choose Keep personal files and apps and let setup finish.

Both ways, step by step: Reinstall Windows without losing files

If File system error -2018374635 is still there

The box writes nothing to a log of its own. Windows still records failed app starts, and two checks tell you where the damage sits.

1. Press Win + R, type eventvwr.msc and open Applications and Services Logs > Microsoft > Windows > AppXDeployment-Server > Microsoft-Windows-AppXDeploymentServer/Operational. Look for red Error entries at the time the box appeared and note the package name and Event ID.
2. Also check Windows Logs > Application for errors from Explorer.EXE, StartMenuExperienceHost or ShellExperienceHost at that time.
3. Sign in to the test account from Fix 5 and repeat the action. If it works there, only your profile is damaged.
4. Run chkdsk C: /scan in an administrator Terminal only if your own files also fail to open or copy: Check a disk for errors (chkdsk)

• What to send to support: the full message with the address in the title bar, which part of Windows fails and the Windows version from winver. Add the update installed before the error, the event entries above, and what Fixes 1 to 7 showed.
• Where to ask: Microsoft Support or Microsoft Q&A, since the error comes from Windows' own apps.
• When it is not software: repeated blue screens, disk read errors or a drive that disappears point to hardware. Back up first and test the drive and memory: How to test your RAM with Windows Memory Diagnostic

How to keep File system error -2018374635 from coming back

Windows 10 left support on 14 October 2025, so it gets no more fixes for built-in app problems. If you still run Windows 10 22H2, the steps above work the same, but an upgrade to Windows 11 is the lasting route.

Frequently asked questions

What is File system error (-2018374635)?

It is the Windows code 0x87B20C15 written as a negative number. Windows shows the same hex code in its message that it could not activate a Store app, so the code means a built-in app failed to start. You see it when Settings, Start, the taskbar, Notification Center or the touch keyboard should open and does not. Start with Fix 1, then register the apps again with Fix 2.

Is my hard drive or file system damaged?

Almost certainly not. The words "file system" are misleading: the code is about an app that did not start, not about the disk. If your documents, pictures and music open and copy normally, the drive and its NTFS file system are fine. Check the disk only when your own files also fail to open, File Explorer shows read errors, or blue screens keep coming back. Back up first, then run CHKDSK.

Why can I not open Settings, and how do I fix it without Settings?

Settings is itself a built-in app, windows.immersivecontrolpanel, and it is the one that most often fails with this code. You do not need Settings for the fixes. Open Task Manager with Ctrl + Shift + Esc for Fix 1, and start an administrator PowerShell from Task Manager's Run new task for Fix 2. For updates and restore points, use the recovery screen you reach by holding Shift while you select Restart.

Why are my taskbar icons gone and Start not working?

The taskbar and Start run in the Windows Explorer and Start menu host processes. When they hang after an update or sleep, the taskbar shows no app icons and Start does not react, and any app they try to start fails with this code. Restarting Explorer and ending the two host processes in Task Manager (Fix 1) usually brings them back. If it keeps happening, register the shell apps again with Fix 2.

What does ms-wpc://appblock or ms-actioncenter in the title bar mean?

It is the address of the built-in page Windows tried to open. The address ms-actioncenter is Notification Center and quick settings. The address ms-wpc://appblock is the page that family safety settings show when an app is blocked or limited; in the box we have, it named the Shell Input Application, the touch keyboard. If you use a child account in Microsoft Family, check the app limits first. Otherwise, the fixes are the same: Fix 1, then Fix 2.

Will these fixes delete my files or apps?

No for Fixes 1 to 5 and Fix 7: restarting the shell, registering the apps, updates, SFC, a new account and a repair install keep your files and installed apps. System Restore (Fix 6) keeps your personal files but removes programs and drivers installed after the restore point. Reset this PC with Keep my files keeps your files but removes installed apps, so back up before it.

Does this error happen on Windows 10 and Windows 11?

Yes. The reports on Microsoft Q&A and Reddit we found came from Windows 10, one of them right after an update. The same box can appear on Windows 11, where Settings, Start and quick settings are built-in apps too. The fixes are the same; only some menu names differ, which the steps say. Windows 10 left support on 14 October 2025, so an upgrade is the lasting route there.

What about file system error (-1073479340) or -2147219200?

Those are different codes in the same kind of box, so they have different causes. In hex they are 0xC0040154 and 0x80040900. We did not research them for this page, so we give no fixes for them here. If one of them appears together with -2018374635 when Settings or Start fails, Fix 2 and Fix 4 are still a safe first step, because they repair Windows' built-in apps and files.

I searched in another language. Is this the same error?

Yes. People search for this box in Russian ("ошибка файловой системы 2018374635 windows 10 как исправить", "как исправить"), Portuguese ("tá dando esse erro", "aparece isso"), Spanish ("que significa"), Turkish ("soru ne"), Vietnamese and Korean. The code -2018374635 is the same in every language of Windows, and so are the fixes. This page is in English only. Searches for ripontelecom.com or ChatGPT are not about this error; this page covers only the Windows message.

How do I fix this issue if nothing works?

Work down the fixes in order: a shell restart, registering the apps, the last update, SFC and DISM, a new account, System Restore and a repair install. If a repair install (Fix 7) also fails, collect the event entries from the section above and ask Microsoft Support. Reset this PC with Keep my files is the final step, after a backup.