Here are some of the ways with which you can disable the Windows 10 update.
Method 1: Registry Value Change
This method is meant to be used only if you have experience with registry editing. It's simple and quick. And you can easily remember how to turn it on and off. Also Windows 10 won't over ride the changes made here.
Follow the steps here.
1. In windows search type "regedit".
2. Open registry editor.
3. Find the key here : "HKLM:SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\"
4. Edit the value with either 0 or 1.
5. Save the changes.
Method 2: Services
Windows 10 basically registers an update service. You can disable it in order to stop the updates. Here is the process to follow.
1. Go to Control Panel > Administrative Tools > Services.
2. Find Windows update service.
3. Edit startup type to "disable".
4. Click Ok.
That's it and this change should stop the Windows update services.
Method 3: Metered Connection
This is simple method but Windows 10 does over ride some of the time and run the background update. I think you can use this if you have access to wifi some of the times. Here's the process for the same.
1. Click on Windows logo > Menu > Settings.
2. In settings find Advanced option.
3. Uncheck "give me updates .... " option.
4. In drop down menu choose "Defer upgrades".
Depending on Windows 10 version you may have, some options may or may not work for you. In such case, just use the registry editing method is the best to check.