Hi
from motherboard USB specs
Intel® Z270 Chipset :
6 x USB 3.1 Gen 1 port(s) (4 at back panel, blue, 2 at mid-board)
Intel® Z270 Chipset :
6 x USB 2.0 port(s)
ASMedia® USB 3.1 controller : *7
1 x USB 3.1 front panel connector port(s)
ASMedia® USB 3.1 controller :
2 x USB 3.1 Gen 2 port(s) (Type-A + USB Type-CTM, Support 3A power output)
maybe none of the USB 2 ports come to the front of your case.
If there are none on the back panel then you may need a 'usb 2 back plate to motherboard bridge cable'
There are procedures to add the USB 3.0 driver to Win 7 but for latest motherboard chipsets & intel 7th generation CPU you are best off with Windows 10 as Microsoft & Intel does not want you to use Windows 7 and blocks updates
(8) Windows® 8.1 64-bit and Windows® 7 32/64-bit are only supported when using 6th Generation Intel® Processors
regards
Mike Barnes