OSX Yosemite breaks Bootcamp

Hi ckapitanj

I installed Windows 8 using Bootcamp and OS X Mavericks. I upgraded to OS X Yosemite and also found that Windows 8 didn't load, and instead only displayed the characteristic blue windows on the screen. After searching for answers on similar issues, it looked pretty bleak. However, I restarted my iMac and launched Bootcamp assistant. One of the options opted for "Download the latest Windows support software from Apple" and I only selected that option. I had a Fat 32 formatted 16 GB external flash mounted and Internet connection and proceeded. After it downloaded all the necessary files a message along the lines of "use these files after installing windows" appeared in a window. Since I have already installed Windows 8 using Bootcamp on Mavericks, I thought that all of this was for nought. However, I restarted my iMac pressing alt in order to switch to the Windows partition again. Only now it tried to configure and repair the windows. After everything finished another message along the lines of "unable to start windows, do you want to restore from a previous situation" or whatever, I opted for "Restore". The same blue windows appeared. Being frustrated I switched of my iMac and pressed alt again in order to select the Windows partition only to find it launching perfectly.

I don't know if this will work for you, but it sure worked for me.

Dear iPodtouch245

I followed your instructions, steps 1 to 7, but I could not see USB named Windows, I can only see UEFI Boot

I am using Mac OS Yosemite, Macbook pro 17'' late 2011

Hardware Overview:

Model Name: MacBook Pro

Model Identifier: MacBookPro8,3

Processor Name: Intel Core i7

Processor Speed: 2.4 GHz

Number of Processors: 1

Total Number of Cores: 4

L2 Cache (per Core): 256 KB

L3 Cache: 6 MB

Memory: 16 GB

Boot ROM Version: MBP81.0047.B2C

SMC Version (system): 1.70f5

Serial Number (system): C02HQ0FHDV11

Hardware UUID: BDD8CE41-E0EB-5F5C-AEF3-DCD3462141D6

Sudden Motion Sensor:

State: Enabled

Any help ?