The genuine prevhost.exe file is a software component of Microsoft Windows Operating System by Microsoft Corporation. The genuine "prevhost.exe" is a Microsoft system file residing in "C:\Windows\System32" which should not be removed. It is an important component of the Windows operating system's ability to use Preview Handlers. These lightweight utilities, each custom-designed and specially registered for one file type, (e.g., ".xlsx" for Excel workbooks), enable applications like Outlook or Explorer to present a rich read-only preview of such files in the "reading pane" without starting their associated application. These are usually DLL's for which "Prevhost.exe" is Microsoft's default "COM surrogate" allowing the Handler to run "out of process" so that if an error occurs only the surrogate terminates, not Explorer or Outlook. (The "COM surrogate" method also enables previewing of files elsewhere on a network.) On a 64-bit system, a version of "prevhost.exe" exists in "C:\Windows\SysWOW64" to interface with 32-bit Preview Handlers; the Handler's registry data must specify that version's CLSID as its surrogate.
PrevHost stands for Preview Handler Surrogate Host
The .exe extension on a filename indicates an executable file. Executable files may in some cases harm your computer. Therefore, please read below to decide for yourself whether the prevhost.exe on your computer is a Trojan that you should remove, or whether it is a file belonging to the Windows operating system or to a trusted application.
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Description: The original prevhost.exe from Microsoft is an important part of Windows, but often causes problems. The file prevhost.exe is located in the C:\Windows\System32 folder or sometimes in a subfolder of C:\Windows.
Known file sizes on Windows 10/11/7 are 31,232 bytes (64% of all occurrences), 24,064 bytes and 8 more variants.
The file is a Windows system file. The program has no visible window. It is a trustworthy file from Microsoft.
Therefore the technical security rating is 3% dangerous, however you should also read the user reviews.
Is prevhost.exe a virus? No, it is not. The true prevhost.exe file is a safe Microsoft Windows system process, called "Preview Handler Surrogate Host".
However, writers of malware programs, such as viruses, worms, and Trojans deliberately give their processes the same file name to escape detection. Viruses with the same file name are for instance Virus:Win32/Virut.EPO (detected by Microsoft), and PE_VIRUX.R-1 (detected by TrendMicro).
To ensure that no rogue prevhost.exe is running on your PC, click here to run a Free Virus Scan.
How to recognize suspicious variants?
If prevhost.exe is located in a subfolder of the user's profile folder, the security rating is 68% dangerous. The file size is 7,088,640 bytes.
The prevhost.exe file is not a Windows core file. The program is not visible.
Prevhost.exe is able to manipulate other programs.
If prevhost.exe is located in a subfolder of "C:\Program Files", the security rating is 100% dangerous. The file size is 225,280 bytes.
The program starts upon Windows startup (see Registry key: RunOnce, Run).
User opinion: dangerous It is not a Windows system file. The program is not visible.
prevhost.exe appears to be a compressed file.
Important: Some malware disguises itself as prevhost.exe, particularly when not located in the C:\Windows\System32 folder. Therefore, you should check the prevhost.exe process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.
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User Comments
It is not a windows program, i'm running 64bit windows 7 and this "prevhost" is 32bit. If it were a windows application, it'd also be 64bit.
It started causing problems with the printing of PDF files in AutoCAD. I would have to plot to file, which created a .plt file...I had to change it to a .pdf and would have to go to the task manager and end the process of prevhost.exe...all in all, a real pain Tom
When it runs m's computer lags. It's like it's processing something else. I don't trust this Preview Handler Surrogate. It's like it's extracting data from your computer. Peter
Summary: Average user rating of prevhost.exe:
based on 4 votes with 4 user comments.
One user thinks prevhost.exe is essential for Windows or an installed application.
One user thinks it's neither essential nor dangerous.
One user suspects danger.
One user thinks prevhost.exe is dangerous and recommends removing it.
Best practices for resolving prevhost issues
A clean and tidy computer is the key requirement for avoiding problems with prevhost. This means running a scan for malware, cleaning your hard drive using 1cleanmgr and 2sfc /scannow, 3uninstalling programs that you no longer need, checking for Autostart programs (using 4msconfig) and enabling Windows' 5Automatic Update. Always remember to perform periodic backups, or at least to set restore points.
Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the 6resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or executing the 7DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.
To get your computer running as fast as it did on day one, you can 8reset your PC. Your personal files will remain intact, but any programs you installed will need to be reinstalled.
To help you analyze the prevhost.exe process on your computer, the following programs have proven to be helpful: ASecurity Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. A good Bantivirus software detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.
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User Comments
(further information)
Tom
Peter
Summary: Average user rating of prevhost.exe: based on 4 votes with 4 user comments. One user thinks prevhost.exe is essential for Windows or an installed application. One user thinks it's neither essential nor dangerous. One user suspects danger. One user thinks prevhost.exe is dangerous and recommends removing it.