Windows and Mac on external bootable drive

Question

Hi,
I am looking for a way to have two partitions on an external drive, one being a bootable Mac partition, the other a bootable windows 7 partition. The two partitions will be used on two separate computers (I have a Mac that I will use the Mac partition with and I have a pc that I will use the windows partition with). I do not need to be able to access the windows partition from the Mac, or the Mac partition from the windows machine.
Is this setup possible? I have looked on the Internet but am getting conflicting theories. Will it work if I format the first partition is hfs+ and install Mac on that, then format the second as ntfs and install windows 7 on that? What partition scheme would I have to use?
Cheers.

Answer 1

Let me see if I read things right...
You have an external dirve with a MacOS partition and a Windows 7 Partition (most likely a drive that used to be in a Mac and had BootCamp on it).  You want to copy the Mac Partition onto a Mac, and copy the Windows Partition onto a PC and use the two separately.  Is this right?
If so, the Mac side is fairly easy,  assuming that the version of MacOS installed on that external drive is as new as (or newer) that the version shipped with the Mac you are trying to copy it to.  I personally prefer SuperDuper for cloning my Mac volumes, but a number of other people use Carbon Copy Cloner (CCC).  Both tools work great for cloning one MacOS partition to another.  I use this to keep a regular backup of my MacOS volume, in case of a disaster.
The Windows side isn't quite as easy, but it is generally possible.  If you try to use the Windows Backup utility to make a partition backup of your Windows instance on the external drive, it will work, but it will also try to do a sector copy of the MacOS partition as well, but it doesn't do that so well.  For Windows systems, I tend to use a third party tool for my backup images.  It's called Acronis True Image.  If you connect the external drive to your PC, and run Acronis True Image, it will let you create a backup clone image of the Windows 7 partition on the external drive.  Since the drive will be GPT (for MacOS) and not MBR, you may need to spring for the Plus Pack for True Image to be able to backup the volume on the external drive.  I would suggest the Plus Pack anyway, because I believe it also has the support to restore the backup image to different hardware.
When you install Windows, it stires information about the hardware in your system, and the drivers it need to load to properly boot.  If you significantly change the hardware, Windows won't boot, and will crash loading drivers leavign you unable to boot the Windows instance.  I know that Windows XP had an installation option which was called a "repair install" which would boot from the install CD and wipe the hardware section of the registry clean, and then re-run the hardware detection phase of the install, but it would not touch the user installed software (unless it hooked into the hardware layers).  I'm sure that similar exists in Windows 7, but I haven't had to use it myself, so I'm not sure how you would use it.  I had mentioned the Plus Pack for Acronis True Image, because it assists you with this component.
In the end, you can do what I think you are trying to do, but the Windows side isn't near as easy to do as the MacOS side. I would suggest that you consider starting the PC with a clean install of Windows 7, and user the migration tools, or just install the apps and copy the data manually...