If you have IE10 installed and want to remove it open Windows Update, then View update history, select Installed Updates at the top, then scroll down to find Internet Explorer 10, click on it and then click on Uninstall in the bar next to Organize towards the top of the window. That should revert IE to 9. To stop it updating again go to search box, type update and in the list click on Windows update. Click on 'Change settings' and under 'important updates' select 'Check for updates but let me choose whether to download and install them'. You can then right click IE 10 update and select to 'hide this update'. This will mean that IE10 update won't be offered again until you need it to be.
OnePlus 5T review: Hands-on