No, it's not custom made laptop (Dell E6440).
I know that Intel Skylake (6th gen) officially support Windows 7 and best proof is this driver: https://www.intel.com/content/www/us/en/download/18799/intel-graphics-driver-for-windows-15-45.html
Btw, check release date!
One more thing, here someone is confirming that i7-7700K is working with Windows 7: https://www.sevenforums.com/drivers/405289-i5-7200u-graphics-driver-windows-7-a.html
i5-7200U is from the same generation (7th gen aka Kaby Lake) as desktop CPU above.
https://forums.overclockers.co.uk/threads/installing-intels-kaby-lake-drivers-on-a-windows-7-laptop.18779373/