Method A:
The easiest way is to disallow "GoogleUpdate.exe" to access Internet using your system Firewall. You can create a new rule for it.
Method B:
If you don't use a firewall or don't want to use the first method, then you can use following steps to permanently remove the "GoogleUpdate.exe" file from your system but remember that after removing the file you'll no longer be able to update the Chrome web browser using its built-in update function. You'll need to manually download the new version.
1) First disable "GoogleUpdate.exe" from system startup. Type msconfig in RUN dialog box and press Enter. It'll open "System Configuration" window. Now goto "Startup" tab and uncheck "GoogleUpdate" from the list.
Apply the changes and restart your system.
PS: You can also use Registry Editor or any other 3rd party utility to remove startup entry. Windows Defender can also do the job.
2) Now we'll need to remove the scheduled task created for GoogleUpdate.exe from our system. Open "Scheduled Tasks" or "Task Scheduler" from Control Panel or Programs menu. You can also run it by directly providing "taskschd.msc" command in RUN dialog box or by opening "%windir%\Tasks" folder.
Now look for the "GoogleUpdateTaskUser" task and delete it.
XP:
Vista:
You can also disable the task instead of deleting it.
3) Now the last thing. We'll need to remove the "GoogleUpdate.exe" file permanently so that it doesn't add its entry in startup.
Go to the following folder:
C:\Documents and Settings\Administrator\Local Settings\Application Data\Google\Update
Replace C: with your system drive where Windows is installed and replace "Administrator" with your user name in Windows.
In the above folder, you'll find the "GoogleUpdate.exe" file. Delete the file.
If you find any difficulties in deleting the file, then make sure GoogleUpdate.exe is not running in background, if its running then End Task of it using Task Manager and then try to delete it again.
4) That's it. Now you'll no longer see "GoogleUpdate.exe" file in background process list.
You can also download and install the Offline installer of Google Chrome which doesn't include the "GoogleUpdate.exe" file:
Chrome Offline Installer: Full Standalone Installer Without Google Update
Or you can use the Portable version of Google Chrome which doesn't need to be installed:
Download Portable Version of Google Chrome, No Need to Install
Source: How to Remove Annoying GoogleUpdate.exe Background Process After Installing Google Chrome?
Best Answer
Download a windows group policy template "Google Update Administrative Template" from Google Site.
Open the editor by typing "gpedit.msc" into the search button on the start menu and click the resulting link
Navigate to User Configuration - Administrative Templates
Right click on Administrative Templates, select add/remove templates from menu bar.
In the popup box click add button and navigate to where you downloaded the GoogleUpdate.adm file and then click close button
You should find a new entry under Local Computer Policy - Computer Configuration - Administrative Templates - Classic Administrative Templates called Google
Navigate to Administrative Templates - Google - Google Update - Applications - Google Chrome.
Right click on Update Policy Override and select edit.
Click enabled button and in the scrollbar list under Policy choose Updates disabled and click OK
To be sure that update not occur, Go to Start > Run > msconfig > Startup > Disable GoogleUpdater.exe
You have now stopped Google Updater from checking for updates for Google Chrome