prevhost.exe

Windows ProcessMicrosoft Corporation

Catalog search terms prevhost, preview handler host, preview pane host

WindowsSystem Component

Preview Handler Host. Explorer dey load IPreviewHandler objects here so dat preview crash no go bring explorer.exe down.

Wetin you need know

prevhost dey isolate preview handlers so dat PDF preview crash no go kill Explorer.

prevhost.exe na di surrogate host for Explorer preview handlers. Di preview pane dey load IPreviewHandler inside dis process on purpose. explorer.exe dey remain di shell. Outlook fit use di same isolation idea. To end prevhost go make di pane blank, no be di desktop.

E safe?: Check the running file path, signature, and publisher. Name alone no fit confirm say e safe.
Same tin as Explorer?: No. Explorer na di shell
Crash on top PDF?: Na di handler die, no be di desktop

Feex tok say

If Explorer continue to run and na only di preview pane turn white, I dey treat am say na prevhost dey do di job. I dey off di pane first as test before I restart di whole shell.

Wetin bi prevhost.exe?

prevhost.exe na di Preview Handler Host. Explorer dey tell am make e load IPreviewHandler so dat if PDF or Office preview crash, e no go kill explorer.exe. No be Explorer.

Wetin e dey do?

E dey host di preview DLL for di file type wey you select. Di folder window, taskbar, and desktop dey remain inside explorer.exe. Search preview no be SearchFilterHost.

Wetin make am dey run?

Di preview pane (Alt+P) or viewer wey be like am ask for preview. Two copies fit dey: one low integrity, one for handlers wey choose say make dem no join. If pane no dey, e mean say dis host suppose dey idle.

Wetin make many copies dey?

Two prevhost.exe copies fit dey, one for low integrity and one for handlers wey choose say make dem no join. explorer.exe na still di shell, no be di preview host.

Inspect the running instance

Inside Windows PowerShell, this read-only query show matching process IDs, creation times and executable paths on this PC. (pcm)

Get-CimInstance -ClassName Win32_Process | Where-Object { $_.Name -eq 'prevhost.exe' } | Select-Object ProcessId, ParentProcessId, CreationDate, Name, ExecutablePath | Format-List

No result or a path we no fit access is inconclusive. Protected processes fit restrict access, and process IDs fit be reused. Keep personal paths local. (pcm)

Use the file-identity guide to compare signatures and product metadata. A filename alone no fit establish safety. (pcm)

E dey safe?

Check dis running file

System32 prevhost.exe na di Microsoft surrogate. prevhost.exe inside codec pack no be dat one. If crash happen here, na di preview handler, no be proof say virus dey inside Explorer.

Compare the recorded location with the actual file. A familiar folder alone no fit establish identity. (pcm)

C:\Windows\System32\prevhost.exe

IPreviewHandler isolation
Explorer dey remain explorer.exe
Low IL by default for handlers

I fit end am?

Preview pane dey go blank

To end prevhost.exe dey unload dat preview. Explorer suppose keep di window. Dat one na di opposite of ending explorer.exe, wey dey drop di shell.

I fit comot am?

No delete prevhost.exe. Off di preview pane or comot di bad preview handler. To delete explorer.exe sef wrong.

E suppose start with Windows?

To open preview dey start am. E no be Startup Apps entry.

Measure resource use

Measure the current process rather than assume a universal baseline
CPU and memory	Compare several observations for the same PID and workload. This entry get no independently measured universal baseline. (pcm)
Disk and network	Attribute activity to the actual process and current task; a filename alone no fit establish expected destinations or transfer volume. (pcm)

File information

prevhost.exe file information
Executable name	prevhost.exe
Recorded installation path	C:\Windows\System32\prevhost.exe
Publisher	Microsoft Corporation
Signature check	Inspect the actual file; this entry no dey certify its certificate identity. (pcm)

Common wahala dem

Preview pane crash loop on top one extension

Dat extension IPreviewHandler don bad. As Explorer still dey up, dat na isolation dey work. Disable di pane or update dat previewer.

People dey restart Explorer for white pane

End prevhost first. To restart di shell na bigger hammer pass wetin dem design di host for.

How to troubleshoot

Diagnose before you change anything wey fit scatter things.

Alt+P to turn off di preview pane as test

If Explorer come dey calm after dat, na di handler get di bug. Update di PDF or Office previewer. No replace explorer.exe.

Take note of di file type wey dey kill di pane

Di handler dey registered per extension. SearchFilterHost parsing for di index na different isolation box.

Technical details

prevhost.exe technical details
Image name	prevhost.exe
Role	IPreviewHandler surrogate host

Check the identity of running file

A filename alone no fit establish safety. Verify the actual path, signature and product identity. (pcm)

Sources and verification

Recorded source label: August 2026. Dis label no establish independent verification. How we dey do research.

Microsoft Learn: preview handlers · Prevhost.exe na di out-of-process surrogate
Microsoft Learn: building preview handlers · Handlers dey run out of process from Explorer
Foxhole process map · First-party samples on top Windows PCs. No be lab benchmark.
Microsoft Sysinternals: Sigcheck · Dey explain how to check file signatures. Dis reference no establish the identity or safety of any particular running file.
Microsoft: Get-CimInstance · Read-only local process-query method. (pcm)
Microsoft: Win32_Process properties · Documents process IDs, executable paths, creation dates and parent-ID reuse. (pcm)

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