Regarding a process called CISVC.EXE

I am using Windows 2000 Professional. In the Task Manager, under the Process Tab, there is a process called CISVC.EXE. it is constantly using up 99% of the CPU. Sometimes it gets down to 49 %

So what is the is process called CISVC.EXE.
ShouldI go ahead and end the process?

Thanks;

Tony