No windows OS below Windows 10 is supported on kaby lake. Thus, there are no drivers.
Also, "any help" would be "support", and windows 8.1 is not supported.
It is true that, in some cases, there are drivers/packages that cover multiple Windows generations and thus can support Kaby Lake on older version of Windows. This is NOT the case for graphics, however. There is no driver for Intel HD Graphics 630 for older versions of Windows (i.e. other than that for Windows 10).