sihost.exe

Windows ProcessMicrosoft Corporation

Also called sihost, shell infrastructure host

WindowsSystem Component

Shell Infrastructure Host. It runs shell flyouts such as the hardware indicators and some Action Center surfaces.

What you need to know

This hosts shell flyouts. explorer.exe still owns the taskbar.

sihost.exe is Shell Infrastructure Host. Volume and brightness flyouts, and some notification surfaces, run here. Ending it does not restart the whole desktop the way restarting Explorer does.

Safe?: Yes, in System32
Should I end it?: The shell UI will glitch
Same as explorer?: No. Explorer is the desktop shell

Feex says

If the volume HUD is stuck on screen, I look at sihost before I reinstall Windows. That host can be restarted. The taskbar still belongs to explorer.exe.

What is sihost.exe?

sihost.exe is the Shell Infrastructure Host. Microsoft uses it for in-session shell UI that is not the full Explorer process.

What does it do?

It draws transient shell chrome: volume overlay, some Action Center pieces, and related input. It does not enumerate your Documents folder.

Why is it running?

You signed in and the shell session started. A missing sihost means flyouts fail while the desktop icons may still work.

Is it safe?

Usually safe

The legitimate host is in System32. An sihost.exe next to a toolbar installer is not Shell Infrastructure Host.

A legitimate copy normally runs from:

C:\Windows\System32\sihost.exe

Expected publisher: Microsoft Corporation
Started with the interactive shell
Not a replacement for explorer.exe

Can I end it?

Restart if the HUD is stuck

Ending sihost.exe can recover a stuck volume overlay. The process should start again with the session. Ending it every hour is not a tune-up.

Can I remove it?

Do not delete sihost.exe. Shell flyouts will fail until Windows repairs the file.

Should it start with Windows?

The interactive session starts it. It is not meant to be unchecked in Startup Apps.

Normal resource behavior

These are contextual labels, not universal averages.

CPU: Low except when a flyout animates or a shell extension misbehaves
Memory: Small
Disk: Low
Network: None by itself

File information

sihost.exe file information
Executable name	sihost.exe
Common legitimate path	C:\Windows\System32\sihost.exe
Publisher	Microsoft Corporation
Signature expectation	Signed by Microsoft Windows

Common problems

Stuck brightness or volume graphic

Restart sihost.exe, then Explorer if the taskbar is also stuck. Two hosts, two steps.

High CPU with a third-party overlay

GPU overlays and shell extensions can poke this host. Test a clean boot before you blame System32.

Troubleshooting

Diagnose before you change anything destructive.

Restart sihost, then check Explorer

If only flyouts are broken, sihost is the first restart. If the taskbar is gone, that is Explorer.

Do not replace the file from a "DLL fixer"

Use SFC or DISM after you confirm corruption, not a download named sihost.

Technical details

sihost.exe technical details
Image name	sihost.exe
Role	Shell Infrastructure Host

Sources and verification

Reviewed by Feex editorial. Last verified August 2026 Status: Feex Reviewed. How we research.

Microsoft Support: Windows · Public support naming
Microsoft Learn: Windows · Primary Windows documentation
Foxhole process map · First-party samples on Windows PCs. Not a lab benchmark.

Was this article useful?

A yes or no is enough. Pick a reason if you want, or add a short note.