What is a printer spooler? My computer will not go into standby because it says check printer spooler.?

Answer 1

A print spooler is a piece of software that collects the bits you're sending to your printer when you print a document. It then sends them on to the printer. It can queue up several print jobs. Without it, there would be a direct interaction between your printing of a document and the physical actions of the printer. Spooling decouples the two.

If you can't go into standby properly, it most likely means you have unfinished print jobs. Find your printer management software and cancel any outstanding jobs.