Mountain Lion Boot Camp-assistant Windows Partition

I tried to install Windows 8 64-bit and Windows 7 64-bit on a seperat partition on My MacBook Pro 2011 15" using Boot Camp-assistant on Mountain Lion.
I got some errors like when rebooting and trying to enter the install-disk it says: "No bootable device ..."

I have already tried solutions with different flashdrives it did not work for me. I also tried with a optical drive - Windows 7 DVD install-disk - which also did not work for me.

It has worked for me before some time ago but that time I had Lion or SnowLeorpard on my Mac.

I don't know if there is a bug or something like that in the new OS - Mountain Lion?

Thanks.

For more details about my error go to: Mac How To : Bootcamp Windows Partition Problem

The Solution

None of the solutions that I have tried worked for me so I ended up recovering the whole Mac OS, unfortunately it didn't help.
But I may have found the reason to my problem on this post:
https://discussions.apple.com/message/15940863#15940863

The problem is that you have to use a certain DVD-drive(dual layer) and since my MacBook Pro's internal DVD-drive does not work I have used an external DVD-drive which is much likely causing the problem. Therefore the only solution (in my case) is to use a proper DVD-drive.