How did you do that? I can't seem to get the bootcamp 5 installer to run under Windows 10
I haven't had to do this for a few years so a bit rusty on details but can point you in the correct direction
You can edit the bootcamp setup installer file so it does not check what version of windows you are running, just google for this and you will find easy instructions on how to do this, but make sure you have the correct version of bootcamp for your system config
Some of the drivers can be run manually to update by simply looking at the directory/files on the usb for the set-up or exe files etc, but this method will not cover all the drivers eg I think the main bootcamp control panel on the system tray is not installed this way
A few can be installed by using update driver from control panel/system and pointing to the directory on your usb
Hope that helps sorry I can't be more specific for you but editing the install file is by far the simplest and most complete if windows bootcamp set-up is failing due to the windows version