MacBook Pro Retina does have a serious issue with Bootcamp and the installation drivers. There are may home remedies and work arounds that have worked for some but not others.
The below steps work for sure for a MacBook Pro Retina. For this procedure to work you need to have a DVD Drive and a Win 7 64 bit DVD (Pro or Ultimate). You will also need to be willing to learn a bit more about your Mac and Win 7.
This is for someone who knows their way around a Mac and Win 7 as you will have to move files, adjust settings, run commands, and run executable files.
The only reason to have the Bootcamp USB drive is to have the Apple Drivers. We can boot from a Win 7 DVD and then run the Bootcamp setup.exe command to install the apple drivers after Win 7 is installed.
1. Run Repair Disk Permissions prior to running bootcamp. Don't bother to run the Verify.
2. Restart the Mac and press Command+S to start single user
3. Type /sbin/fsck -fy (notice the space between the k and the -f. This command will fix any issues with permissions, free space, fragments, etc that the disk utility does not see or is unable to fix. Run this command regardless of the results in permission repair. Steps 1-3 will prevent errors during Boot Camp Assistant.
4. Type reboot to reboot the Mac.
5. Run Boot Camp Assistant and follow the steps. You need the ISO image file from Microsoft. The ISO image file needs to be the same edition as the Win 7 DVD. You can also make an ISO of the Win 7 DVD (this is the preferred method). Make sure that you increase the size of the Windows Partition to at least 50 Gig. Windows needs virtual memory and will be sluggish with 20 Gig.
6. The Mac will restart automatically after the partition process is complete so don't panic. Make sure that the Win 7 DVD is in the drive and the drive is connected to the Mac.
7. THIS STEP IS CRITICAL. Press any key to boot from CD or DVD. If you screw up then you need to restart the Mac and press the Option key to get to the selection menu. Select the DVD drive NOT the USB that you made with bootcamp, and again Press any key to boot from CD or DVD. Using the USB to boot Win 7 will give you errors and won't allow you to install. Bootcamp formats on FAT 32 and we need NTFS for Win 7. Something is wrong with the NTFS format command in the Bootcamp USB drive or is a Mac Retina issue, I don't know.
8. Go through the menus. When you get to the partitions you will see the Bootcamp partition at the bottom. Highlight it and press Format from the Advanced choices. This will convert it to NTFS. Don't worry about the name change. If you get an error then you are not using the Win DVD for installation and must refer to step 7.
9. Finish installing Win 7 by following the instructions.
10. Login to Win 7 and open a window that shows Computer. If you don't see the USB drive then unplug it and plug it back in to be recognized.
11. Go to the Bootcamp folder and click the setup.exe this will install all the drivers dowloaded during the Boot Camp Assistant set up. Restart Windows after its done.
12. If you notice that a device is not functioning properly then go to the USB Drive and the $WinPEDriver$ folder. There you can run each of your devices installation program individually by just clicking on it and following the prompts.
13. You will need to tweak the windows hardware settings afterward. The display settings are usually off initially.
This will work. If you have issues then retrace your steps and make sure that you are booting from the Win 7 DVD.
Good luck!