64 bit both versions. I was with Apple support for several hours yesterday, unfortunately nothing. All I get is a black screen so I cannot even start the windows install. I have tried using different monitors from different brands and the same problem.

Firstley is you install uSB usb 3 or 2 for some reason you can only use usb 2.

What I was told when I was try with our success to install boot cam on macbook pro was to go to boot camp Assistant. insert your usb drive and have your windows install media to hand. make sure that create windows 7  or later is selected as well as download latest support software from apple. But un check install windows 7 or later. when this has finished Restart the machine. go back to the boot camp assistant then check install win 7 or later and un check the other 2 boxes. divide the drive as required. when asked for a install portion select boot camp redbreast location format it re-highlight that partition then it should install

It finally worked. I had to download an original ISO of Windows 8.1 Pro With Update from Microsoft MSDN Suscriptions. Created the USB with the Bootcamp Assistant and the ISO, downloaded the drivers, partitioned the disk, and for some reason it worked this time (Windows 7 never worked, and neither did Windows 8).

Good luck to all having this nightmarish issue.

Doesn't work at windows7. I did it and the formation works, but after this I got the message there is no access to disk. I think, there is a problem with the partition table und windows. I installed an old clone with winclone (a lovely tool) and it works. But there is no access to the mac partition from windows. I think a fix is urgently necessary.

Ulf

Do you have access to mac partition from Windows7?

Ulf

No fix today!

About the OS X Yosemite v10.10.1 Update

The OS X Yosemite v10.10.1 Update is recommended for all OS X Yosemite users.

Updating your system

1. You should back up your system before installation. To do this you can use Time Machine.
2. Do not interrupt the installation process once you have started to update your system.
3. You may experience unexpected results if you have third-party system software modifications installed, or if you've modified the operating system through other means.
4. Use Software Update to check for the latest Apple software using the Mac App Store, including this update.
5. Other software updates available for your computer may appear, which you should install. Note that an update's size may vary from computer to computer when installed using Software Update. Also, some updates must be installed prior to others.

You can also download the manual update installer. This is a useful option when you need to update multiple computers, but only want to download the update once. Standalone installers are available fromApple Support Downloads.

About the update

The OS X Yosemite v10.10.1 Update improves the stability, compatibility, and security of your Mac. This update:

• Improves Wi-Fi reliability
• Improves reliability when connecting to a Microsoft Exchange server
• Resolves an issue that may prevent Mail from sending messages through certain email service providers
• Addresses an issue prevents connecting to remote computers using Back to My Mac
• Resolves an issue where sharing services, Notification Center widgets and Actions may not be available
• Addresses an issue that could cause Notiication Center settings to not be retained after a restart
• Addresses an issue that might prevent the Mac App Store from displaying certain updates
• Addresses an issue that could prevent some Mac mini computers from waking from sleep
• Resolves an issue that might prevent Time Machine from displaying older backups
• Addresses an issue that might prevent entering text in Japanese

Enterprise content

For enterprise customers, this update:

• Allows you to append search domains for partially qualified domain names when performing DNS lookups (consult the discoveryd man page for more information)
• Addresses an issue where the Mac App Store might offer an update to Apple Remote Desktop when the latest version is already installed

Security Content

For detailed information about the security content of this update, see Apple security updates.

Last Modified: Nov 17, 2014

Hi evereyone!

Same problem here with a french Mac Mini late 2014 with the latest 10.10.1 update. I prepared the USB bootable drive using boocamp, downloading the driver, etc. and black screen it is when booting from the USB and when choosing the Windows boot at the start.

Is Apple considering these sorts of issues? I can imagine that a bunch of people find the Windows boot possibility useful for softwares that are not available onc Mac.

Using Mac Mini (late 2012).

Upgraded to Yosemite. Existing Bootcamp became unstable.

Did a fresh install of Yosemite.Using Bootcamp tried to install Win 8.1 Pro.

When selecting drive on which to install windows am told drive (Partition 4) is not formatted to NTFS (I checked and it is).

Tried 'Format' on same page, button fails to initialise any format action.

Process fails at this point.

Mac Mini is now a shiny paperweight that runs OS X only.

Knew I should have bought a PC and forget about occasionally using OS X programmes.

Find out this is a problem known to Apple when they released Yosemite.

Find out Apple appear to be doing nothing to expedite a repair.

Epic fail...

I had the same issue with the screen not displaying anything and it just being black. I originally had thunderbolt to dvi adapters connected.  I just swapped the dvi to a vga adapter and I am now able to get the windows setup on boot camp.  I am installing now and hoping I can switch back to my dvi adapters.  I'll let you know.

If you have a Thunderbolt display, use display and plug the usb devices in to display. That way the mac will see the USB devices and won't need the extra drivers to get them to work on the Mac mini.

I have the same problem:

New iMac (just delivered on Thursday) with 3TB fusion drive trying to install Bootcamp with 64-bit Windows 7.

The problem, as I see it, is that Boot Camp Assistant (BCA) and Windows calls for a format of the BOOTCAMP partition to NTFS but then leaves the partition UNTITLED. Windows installs on this partition but the drivers are not installed (probably looking for a BOOTCAMP-named partition to install to. Windows is left with a low resolution desktop and without any drivers for any of the hardware, such as that required for networking. Is there any word from Apple on this? I need to run some of my software on Windows!!

The issue deal with lack of USB3 drivers on the install disk for Windows 7. So our work around was to connect a thunderbolt monitor to the Mini mac and use the USB2 port on the monitor. This way when Windows 7 installs, it USB2 ports on the thunderbolt monitor. Then it will install the devices drives from the USB device that you have the drives on. So this issue with comes from Windows and Apple on how to get the USB3 ports working while install on a Mac mini.

Unfortunately I don't have an external monitor to use. In my case, I am working with an iMac.

I am using a usb2 thumb drive for the bootcamp creation process so I don't think the lack of usb3 drivers in Win7 applies.

I still think the problem lies in the fact that the formatting of the bootcamp partition just prior to the Win7 installation does not keep the name BOOTCAMP for the partition. The Windows Support Software that is downloaded has a script, I think, that looks for a partition named BOOTCAMP (that does not exist after the format) to instal to. So windows 7, that is installed into this unnamed partition is left stranded without the necessary drivers.

IN your case, I assume that your bootcamp partition is named BOOTCAMP , as it should be. Is it?

Out of curiosity, did you do your install with the latest BCA Ver 5.1?