hi all just looking for some advice, trying to install Windows on a New iMac via an external DVD samsung DVD drive. I have tried with both a Windows 7 install disc and Windows 8 , that I have previously used on a PC with success. After selecting the install option via bootcamp assistant, the Mac reboots but goes to a black screen with a single cursor flashing. it does not move from here, I tried rebooting and holding alt to manually select the DVD drive but it then gives an error saying BOOTMGR not found. any ideas? can I even use an external DVD drive? Does the fact I am using a bluetooth keyboard make a difference? ( e.g no drivers to load it or something) I have tried to delete the partition and try again via the bootcamp assistant but that made no difference. thanks in advance.