How can we remove Windows Rollback option from Boot Menu of Windows 10 Build 9926?

You will need to follow these steps to remove the rollback option -

• In the search box type cmd , right click on the command prompt result and click on Run As Administrator.
• Type bcdedit/timeout 0

If, however, you feel you need to have this option you can follow the same steps and replace 0 in timeout with any other number between 1 and 30.
Another option to remove this is as below -

• Select Run command, type msconfig and press enter.
• In the System Configuration window you get, select Boot tab and select Windows rollback (Windows)
• Click Delete.

Note - Microsoft does not recommend this option. You need to try it on your own risk.