Your experience verifies, that Win7 does not give full UEFI mode support.
If I were you, I would switch to Win8.1. The UEFI mode OS installation is a must-do in the near future, because the LEGACY mode (OROMs) will not be supported anymore.
Thanks all, I have the same problem too with Win7 x64 UEFI: http://phota.me/ibpL