Svchost.exe is a generic wrapper program for windows system services.  You will see several of them running at any time on your machine, each can have more than one service under them.  To get details on what services run under each process, you can run "tasklist /svc".  When you get the crash notification, you should check the event log for Service Control Manager events for services that have stopped unexpectedly.  Once you know what services are impacted, you can try to narrow down what might be the problem.  Also, while the popup is up, you can grab the memory dumps out of the temp folders for debugging if you know what you are doing.  That way you can look a the stack trace to find a better idea of what causes the error in the application.