Posted 22 August 2009 - 09:05 PM
Ah, the good ol' svhost.exe! My favorite completely unhelpful process name.
The svhost.exe is also called the Generic Host Process for Win32 Services. I know, helpful, huh?
What these processes do is host other programs inside of them. Generally, these programs are service applications that need to run in the background to provide "services" to other applications. One example is the Windows Audio service, which provides a method for applications to play sounds through the Windows API. Or the DHCP Client Service that allows your computer to automatically get an IP address from your router.
So, as you can see, a lot of useful and necessary services get hosted inside these svhost's. That being said, not everything that can be inside svhost is helpful, necessary, or safe. Many malicious programs install themselves as a service. Many, many, many legit software vendors like to install their own services like updaters and quicklaunchers (I'm looking at YOU Java) that are completely and utterly without purpose or justification.
To see what services are running, go to Start->Run.. and type services.msc then click ok. From this MMC snap-in you can see which services are currently running, which are disabled, which will start up "on demand" and so forth. you can also start/stop services and change their startup behavior. Unless you know precisely what a particular service does, though, leave it alone.