Install Win7 w/ Bootcamp on iMac

As suggested, I read Install Windows 7 and earlier on your Mac using Boot Camp - Apple Support followed the instructions for "Perform a new install of Windows 7"

But, I'm stuck on step 13, using Boot Camp Assistant (BCA) to do the install.

When I launch BCA and click the Continue button I get a popup that says:

The startup disk cannot be partitioned or restored to a single partition.

The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows.

My startup drive is formatted as a single partition using OS X Extended.

How do I change the startup disk to OS X Extended (Journaled) without erasing the content?

Descartes:~ nello$ diskutil list

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *121.3 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_CoreStorage Descartes 120.5 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

/dev/disk1 (internal, virtual):

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS Descartes +120.1 GB disk1

Logical Volume on disk0s2

6E39962E-AEDC-4B28-8AFD-CF2A78893736

Unlocked Encrypted

Descartes:~ nello$ diskutil enableJournal /dev/disk1

Journaling was already enabled for volume Descartes on disk1

Descartes:~ nello$

As you suggested, I booted into Safe Mode and then restarted.

Now, launching Boot Camp Assistant (BCA), I have a new/different/better(?) error:

The startup disk does not have enough space to be partitioned.

You must have at least 50 GB of free space available.

Well, it's true that the internal drive lacks this space.

But, I'm trying to install Windows 7 on an EXTERNAL SSD.

How do I get BCA to consider doing the install on the external SSD?

I'm rather disappointed to hear just now that I can't use Boot Camp Assistant (BCA) to install Win 7 on an EXTERNAL drive.

My original post in this thread said:

I'd like to install Windows 7 on an external (FireWire) drive ….

I'm kinda bummed that only now do I find out that this can't be done with BCA. 😢

I'm trying to do this install on my MacBook Air (13", Mid 2012) with 8GB RAM and 120GB SSD.

I deleted some large files and now have 64G of free space.

I launch Boot Camp Assistant (BCA) unchecked the first two boxes and left checked the last box that says install Windows 7.

BCA successfully created a 32GB Windows partition, the screen flashed a few times as if it were restarting, and then it got stuck on something and displayed an error message that said something like:

No Bootable Device. Please insert disk and press any key

I had my Win Install thumbdrive inserted already so I couldn't figure out what it wanted. I tried powercycling to get back to my OS X partition, but this message kept appearing. Finally, I booted to into Recovery Mode and set the startup disk to OS X; I rebooted into OS X, launched BCA, and removed the Windows partition.

Okay, why didn't the Windows install see my thumbdrive as a bootable device?

How can I tell whether my USB drive is USB3 or USB2?

Drat!

So I have to have a USB2 stick, eh?

But, wait ...

In the image, the SanDisk Cruzer Glide is on the USB *3* bus ... I thought you said that I need a USB *2* drive?!?

What am I misunderstanding?