questions
1. Will this version work if enhanced 1.011 is installed or will that damage the compatibility with Win7 (I had wished to only port the exe across to the GOG MaB version. So that I could play The Last Days of Middle Earth mod).
2. Will a Warband serial key allow such an upgrade to function properly.

The Last Days of Middle Earth mod seems to be the best mod available for MaB and as a Tolkien Fan the only reason that I would play this game!
I am disappointed that GOG has provided this game without a serial key to enable enhancement. This means that it is unmodable and not fit for the purpose that I downloaded it for.

GOG's version is different from the original release, so you might run into trouble using the enhanced versions executable. See here: http://www.gog.com/forum/mount_blade_series/is_the_original_mount_and_blade_the_enhanced_version_of_1011_or_no

But you can use the serial key provided with Warband in conjunction with Enhanced edition. See here:
http://www.gog.com/forum/mount_blade_series/mb_1_serial/post3

Thank you very much.