Try as I may, I cannot get Boot Camp on macOS High Sierra to accept any Windows 7 installer DVD (or ISO) I have tried yet. Although Boot Camp seems to be able to accept a flash drive, when I try one I get the error:
The installer disc could not be found. Insert your Windows installer disc and wait a few seconds for the disc to be recognized.
So, since this is a Mid 2010 MacBook Pro (which has an optical drive) I've tried a legit Win7 SP1 retail DVD (checksum verified), but then I get this error:
Boot Camp only support installing Windows 7 on this Mac. Please insert a USB drive or DVD which contains a full version of Windows 7.
Does that mean "full" as in all editions of Win7, so Home, Pro, Ultimate, etc?? Documentation for this online is very sparse and lacking, I've found.