First, back to the basic.....
Svchost is a host process name for services that run from dynamic-link libraries / dlls. Though we know that, it is not possible to launch any dll directly by clicking it, rather it is to be loaded from a running executable. And that is why svchost helps to do the same.
It is possible to remove / stop some unwanted services, that do not need to be running. And remember, if it shows that high cpu usage on a single svchost then u may restart the services running under that instance also. By pressing CTRL+ALT+DEL to see the task manager / by command line: tasklist /svc.
U may double-click on a svchost instance & select the services tab, where choose to stop one of the services.... or u may sue services.msc for the same purpose.
For better handle, download a free tool called "<a href="http://technet.microsoft.com/en-us/sysinternals/bb896653">Process Explorer</a>", which may help u ! See here as <a href="http://support.microsoft.com/kb/314056">Microsoft Opinion</a>
For <a href="http://itknowledgeexchange.techtarget.com/itanswers/cpu-usage/">Almost Same Thread</a> is here