What is the scheduled task "\GoogleUpdateTaskUserS-1-5-21-...-1004UA" on my Windows 8 computer?

"\GoogleUpdateTaskUserS-1-5-21-...-1004UA" is a scheduled task on Windows 8 system added as part of Windows installation.

You will see "\GoogleUpdateTaskUserS-1-5-21-...-1004UA" listed on Task Scheduler with the following information:

Name: GoogleUpdateTaskUserS-1-5-21-...-1004UA
Location: 
Description: Keeps your Google software up to date. If this task is 
   disabled or stopped, your Google software will not be kept up to 
   date, meaning security vulnerabilities that may arise cannot be 
   fixed and features may not work. This task uninstalls itself when the
Actions: C:\Users\...\AppData\Local\Google\Update\GoogleUpdate.exe 
/ua /installsource scheduler
Triggers: At 4:58 PM every day - After triggered, repeat every 1 hour
History: 
   Information 6:58:22 PM Task completed
   Information 6:58:22 PM Action completed
   Information 6:58:22 PM Action started
   Information 6:58:22 PM Created task process
   Information 6:58:22 PM Task started
   Information 6:58:22 PM Task Engine received message to start task
   Information 6:58:22 PM Task triggered on scheduler

Programe file information about "GoogleUpdate.exe":

File name: GoogleUpdate.exe
File path: C:\Users\...\AppData\Local\Google\Update\GoogleUpdate.exe
File size: 144200 bytes
Last modified time: 9/1/2015 1:07:44 PM
File description: Google Installer
File version: 1.3.28.13
Company name: Google Inc.

"GoogleUpdate.exe" is scheduled to run every 1 hour.

It is recommended to keep "\GoogleUpdateTaskUserS-1-5-21-...-1004UA" enabled as a scheduled task. You can get the updates yourself manually.

⇒Application Scheduled Tasks on Windows 8

⇒⇒Windows 8 Scheduled Tasks