First up: a question. How did you fix the crashing Bootcamp Utility? It would help out this guy: https://discussions.apple.com/thread/5479879?answerId=23523783022#23523783022&ac_cid=tw123456#23523783
Next up: A possible solution (also posted here:https://discussions.apple.com/thread/5479879?answerId=23523783022#23523783022&ac_cid=tw123456#23523783)
=====================
It's possible you have a Windows ISO for both 32- and 64-bit. In this case it's probably detecting the presence of the 32-bit installer and forgets to look for another 64-bit version.
A way to work around this is to not use the Bootcamp Assistant utility by following the listed steps:
The way installing Windows should work either way using the Legacy BIOS mode:
- Get a Windows ISO or DVD and copy the contents over to a freshly fat32 formatted USB stick of at least 4GB.
- Download the Apple Bootcamp Support Software (4.x or 5.x, 5.x only supports 64-bit, get that if you are going 64-bit);
- Copy the content of the Support Software folder over the the same USB stick from the first step. It should fit just right (it did on my 4GB stick with 2MB te spare!);
- Use disk utility to partition your disk. Make sure the partition for Windows is Fat32 and at least 30GB;
- Reboot your machine while holding Option/Alt at the chime;
- You should be able to select either your OSX HDD or your USB stick labeled "Windows" -> Select Windows and press enter or click the arrow;
- The Windows installer should now load, format the previously made Windows partition to NTFS;
- Continue on your way.
Can you try what I typed above? If it doesn't work, can you let me know at what step things go differently than described?
Edit: This is based on the logical conclusion that any Mac that was shipped without ODD should be able to boot from USB.
Edit2:
One other note is that Mac's have trouble booting from USB when multiple USB storage devices are attached. So make sure you connect only one storage device.
=====================
Best of luck to you!