When computer turn on then Microsoft Office 2016 or 2019 start automatically in windows 10 pc. To stop this automatic startup of office program follow below instructions:
How to stop automatic start of office 2016 or 2019 in windows 10
1. Click Start menu and go to Settings.
2. Now click Accounts and then click Sign-in Options.
3. Find 'Use my sign-in info to automatically finish setting up my device and reopen my apps after an update or restart' and off or disable this option.