I had a look at the Dell SupportAssist OS Recovery for OS Reinstallation on a Dell OptiPlex 7040. This is obtainable using the Dell OS Recovery Tool.
Unfortunately the Tool gives no Language Options when Installing Windows 10, installing it in English USA, with USA Keyboard Format and Date Format.
It also gives Windows 10 Version 1803 opposed to Windows 10 Version 1809.
Screenshots are below.
This might be a stupid question but… is the installed Windows version a factory image from Dell (like the one you get on a brand new laptop) or is it a clean Windows installation without the Dell bloatware? I'm asking this because I accidentally deleted the recovery partitions when reinstalling Windows and now I can't factory reset it so this might be the only way to get the factory image.
It is Windows 10 only with Dell Update preinstalled.