I have three disks, one GPT partitioned containing Windows 7 and Debian, the other MBR partitioned containing CentOS, and the other one MBR partitioned, empty. It used to work (loading Windows boot manager using rEFIt) but now after installing CentOS and OpenIndiana on the second drive, Windows won't boot. The logo is displayed briefly and then a text mode scrollbar "Loading files", then back to the rEFIt menu. The only thing that makes it work is if I drop into the UEFI shell and run disconnect XX where XX is the device handle of the other hard drives (obtained from running devices). This makes me think that the bootloader is getting confused about where the Windows partition is. Is there any information on how the Windows UEFI boot loader finds the Windows partition, or is there any logging I can turn on to help troubleshoot this issue?