What year was this laptop assembled?
I don’t have that info but according to Wikipedia, the Dell Latitude E7450 was a 2015 model.
No point in paying more for the Windows 10 Pro version. I picked up a refurbished E7250 with Windows 8.1 Pro a few weeks ago and the first thing I did was install a fresh Windows 10 Pro. Simply download the Windows 10 installer from Microsoft and create a bootable Windows installer on a USB flash drive. Boot to the flash drive, select repair, and delete all the drive partitions. Then boot again and install a fresh Windows 10. It automatically discovers the embedded license key and automatically activates. This also eliminates any bloatware that might have been present.