You can still get windows 7 installs through manufacturers. They sell you an OEM license for windows 10 pro which includes downgrade rights and then slap a windows 7/8 image on the computer and ship it out.
You can go on the DELL website right now and find windows 7 business laptops. In fact, the default selection on the operating system IS windows 7. Example:
DELL 7470 - Operating system:
( ) Windows 10 Pro, 64-bit, English, French, Spanish [subtract $20.00]
(*) Windows 7 Professional English, French, Spanish 64bit (Includes Windows 10 Pro License) [Included in Price]