Problems with Windows/bootcamp/efi? - Helpful collection of solutions
How to create a (legacy/Bios/conventional) bootable Windows installation USB drive:
If for some reason you don't want to use Bootcamp Assistant, you can follow these steps to create your own bootable USB drive.
Diskpart is a Windows command-line tool. To use Diskpart you need to have access to a Windows PC or a Windows Installer (where you can open the commandline prompt by pressing Shift+F10)
How to make an active partition in Diskpart:
1. Open a command prompt (type CMD in the Start Menu search bar, press enter);
2. Type diskpart;
3. Type list disk;
4. Look for the entry of your USB drive and remember it's number (checking disk sizes usually helps in spotting it);
5. Type select disk x, where x is the disk entry you checked in step 4;
6. Type clean;
7. Type create partition primary;
8. Type format fs=FAT32 quick;
9. Type active;
10. You're done, type exit twice. (once to exit diskpart, again to exit command prompt);
To add the Windows Installation files:
1. Mount a Windows ISO (in OSX or windows, doesn't matter);
2. Select all files on the disk;
3. Copy;
4. Open your freshly made USB drive;
5. Paste;
To add Bootcamp Support Software:
1. Download and unpack the Bootcamp Support Software (v5.x for 64-bit)
2. Select all files (Folder: $WinPEDriver$, folder: Bootcamp, file: AutoUnattend.xml)
3. Copy;
4. Open freshly made USB drive that contains Windows Installation files;
5. Paste;
Done.
Note: For EFI installs you don't need to do this. Just format the drive FAT32, copy over your ISO/DVD files, and you're good to go.
How to restore a protective MBR into a hybrid MBR:
If you installed Windows using Bootcamp the conventional way and adjusted partitions afterwards, chances are your Windows no longer boots.
You can fix this by following the link in the fix below and using that program (GDisk) to do the opposite of what is posted. (create a hybrid MBR)
How to restore a hybrid MBR into a protective MBR:
Disk Utility and Bootcamp Assistant automagically create a Hybrid MBR when a partition is formatted FAT32. Because of this you can't install in EFI mode if you used either of these apps to partition your drive.
The solution (check the answer on the linked question):
http://superuser.com/questions/508026/windows-detects-gpt-disk-as-mbr-in-efi-boo t
How to create an EFI bootable Windows 7 USB drive:
Windows 7 is only partially EFI compatible, you may run into problems during installation on a Mac.
Tip: If you're running a HD4000 graphics chip, it's likely you won't get a picture during the installation. Plenty of ways around this (like unattended installs (full thread)) but I advise you to wait for a firmware update (if it ever gets released).
The solution (skip to "Option two" - step 11, the rest is kinda... unnecesary):
http://www.eightforums.com/tutorials/15458-uefi-bootable-usb-flash-drive-create- windows.html
Can't see "Windows" as a USB boot option?:
Try resetting the PRAM.
Source: https://discussions.apple.com/thread/5524707?tstart=0
How to reset PRAM: http://support.apple.com/kb/HT1379?viewlocale=en_US&locale=en_US
