What Is “Spooler SubSystem App” (spoolsv.exe), and Why Is It Running on My PC?

If you poke around in your Task Manager, you’ll likely see an process named “Spooler SubSystem App”, “Print Spooler”, or spoolsv.exe. This process is a normal part of Windows and handles printing. If this process consistently using a high amount of CPU resources on your system, there’s a problem.
by Chris Hoffman via How-To Geek