Copy the file svchost.exe out of this zip file to a key drive. You can then copy it to c:\windows\system32. Reboot and you should be OK.
If you are on xp sp2 or greater, you should be able to tab-complete paths for your xcopy command. THis means you start typing, then hit the "Tab" key on your keyboard, to help autocomplete the path/filename you are looking for. if you don't have tab, remember to put your path for c:\program files\... in quotes, since windows can't execute a command that has a space in it without them being wrapped in " ".
If you don't know xcopy, here is a fast man page.