# what is svchost.exe? **URL:** \ **Category:** Factual Questions\ **Created:** [February 23, 2005, 12:22am UTC](https://boards.straightdope.com/t/what-is-svchost-exe/291438 "2005-02-23T00:22:39Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![James\_Westphal](https://avatars.discourse-cdn.com/v4/letter/j/b9bd4f/32.png) [@James\_Westphal](https://boards.straightdope.com/u/James_Westphal)\ **Post date:** [February 23, 2005, 12:22am UTC](https://boards.straightdope.com/t/what-is-svchost-exe/291438/1 "2005-02-23T00:22:39Z")
This thing has a penchant for using 99% of my CPU, and right now it’s running in 5 instances, three of which are classified as SYSTEM. Anyone know what it is? ---
**Author:** ![Reeder](https://avatars.discourse-cdn.com/v4/letter/r/c6cbf5/32.png) [@Reeder](https://boards.straightdope.com/u/Reeder)\ **Post date:** [February 23, 2005, 12:29am UTC](https://boards.straightdope.com/t/what-is-svchost-exe/291438/2 "2005-02-23T00:29:50Z")
> [@](#): > > Description: > svchost.exe is a system process belonging to the Microsoft Windows Operating System which handles processes executed from DLLs. This program is important for the stable and secure running of your computer and should not be terminated. [http://www.liutilities.com/products/wintaskspro/processlibrary/svchost/](http://www.liutilities.com/products/wintaskspro/processlibrary/svchost/) ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [February 23, 2005, 12:34am UTC](https://boards.straightdope.com/t/what-is-svchost-exe/291438/3 "2005-02-23T00:34:05Z")
> [@James Westphal](#): > > This thing has a penchant for using 99% of my CPU, and right now it’s running in 5 instances, three of which are classified as SYSTEM. Anyone know what it is? It might be good, it might be bad: [http://www.neuber.com/taskmanager/process/svchost.exe.html](http://www.neuber.com/taskmanager/process/svchost.exe.html) > [@](#): > > Note: The svchost.exe file is located in the c:\windows\System32 folder. In other cases, svchost.exe is a virus, spyware, trojan or worm! Check this with Security Task Manager. Note to **Reeder:** Many things masquerade as other things with the same name. Where it resides and where it executes can be very important. If it occupies 99% of your CPU time, it is unlikely to be from Microsoft. ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [February 23, 2005, 12:52am UTC](https://boards.straightdope.com/t/what-is-svchost-exe/291438/4 "2005-02-23T00:52:00Z")
> [@Musicat](#): > > If it occupies 99% of your CPU time, it is unlikely to be from Microsoft. Unless it’s Windows… _runs_ ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [February 23, 2005, 1:10am UTC](https://boards.straightdope.com/t/what-is-svchost-exe/291438/5 "2005-02-23T01:10:00Z")
- - - Microsoft has info on it: short version, it is a system extension process, that other programs use. Having multiple instances running in WinXP and Win2000 is normal. [http://support.microsoft.com/default.aspx?scid=kb;en-us;314056](http://support.microsoft.com/default.aspx?scid=kb;en-us;314056) - Some chat/IM clients and trojans tend to produce this problem (of 99% CPU usage), but _only when you have a network connection enabled_–so if you externally enable/disable your internet connection (like, by turning the modem on and off) and the usage goes up only when you are connected and goes down when you disconnect, then it is this general problem of some network-active program. Then you’d want to see what kinds of chat/instant-messenger programs are running, including Windows Messenger (msmsgs.exe) which has been found to cause this problem. - Normally, the “system idle process” is the process that should be using most of the CPU when you are doing “nothing”. ~ ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [February 23, 2005, 2:01am UTC](https://boards.straightdope.com/t/what-is-svchost-exe/291438/6 "2005-02-23T02:01:55Z")
Svchost.exe is a legitimate Windows application. However, I see over 20 different bits of spyware/viruses that use that filename. You need to where it is running from. The quick way is to click on “Start,” “Run,” and type in “msconfig” (no quotes) and click “OK.” Once msconfig runs, look at the startup tab. If you see svchost.exe as one of the startup programs, you have a problem. A trip to [http://housecalls.trendmicro.com](http://housecalls.trendmicro.com) will fix any virus problems, and you can download Microsoft’s Antivirus program to deal with spyware issues. ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [February 23, 2005, 2:03am UTC](https://boards.straightdope.com/t/what-is-svchost-exe/291438/7 "2005-02-23T02:03:03Z")
Oops – that URL is [http://housecall.trendmicro.com](http://housecall.trendmicro.com)