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P · Nov 22, 2012, 04:50 AM

For the last two years at least, my iMac has been without an internal optical drive. I have the old drive with an external adapter, and that has worked well enough...until now. I have an old Win XP Bootcamp installation that I for some reason decided to upgrade to Win 7. That seems to be near impossible. What I discovered too late (=after deleting the old XP partition to nuke&pave), is that while my iMac 11,1 can boot OS X from USB and can emulate BIOS to boot Windows, it cannot boot Windows (or any other BIOS-using OS) over USB. Some Macs can, including (apparently) my MBA and more recent iMacs, but not this iMac. This means that I cannot boot the install disc no matter what I do.

Things I've tried:

* Booting from the USB DVD: Not possible. Tried several drives.
* Making a USB stick of an ISO with that tool from MS: Does not work, tried several sticks.
* Running the installer from within Parallels, but installing to a Boot Camp partition: When the installer tries to update the boot sector, OS X blocks that and the install stops before it really gets going.
* Just copying the installer to a Bootcamp partition: Does not find anything to boot from. Probably I need to set the boot sector manually somehow, but I can't find how to do that. One suggestion was to use Fusion to boot from the install disc directly, but I can't seem to do that in Parallels.
* Using rEFIt/refind: Doesn't help, although it does at least give me some error messages about what failed
* Using another bootmanager on the same USB stick as the Windows install: Also does not boot.

Any ideas on how to boot that install disc?

cgc · Nov 24, 2012, 02:54 PM

OWC has a replacement iMac superdrive for $59.99.

P · Nov 26, 2012, 12:22 AM

My superdrive works fine, but I removed it to put an SSD there. I could put it back in, but I don't want to have to disassemble the thing again just to get Windows on there. I can do a lot of what I want in Parallels - my question is for when there is a game that I really want to play in Windows that doesn't run well enough in Bootcamp.

cgc · Nov 26, 2012, 09:28 AM

If you cannot find another solution, and it seems you can't then reinstalling and using the Superdrive is your only option. Funny thing is I've installed Windows and Linux on an HTPC via a USB stick. One time I installed a Linux variant that only ran XBMC from a USB stick onto another USB stick. Yet another quirk in the Mac I s'pose.

P · Nov 27, 2012, 05:21 AM

Actually, that my iMac can not boot Windows over USB makes excellent sense - it is from October 2009, and MS had just barely started supporting booting installs over USB. The then brand-new Windows 7 did not boot from USB by default and refuses to install to USB HDDs. The USB download tool, which basically slipstreams a Windows install and a USB driver onto a USB stick, seems to have been launched in some form of beta in August that year, only two months earlier.

The issue with putting the optical back in the iMac is dual:

* There is a vertical sync band cable that really looks like it can't stand too many disassemblies, and I'd have to disassemble it twice more to do this.
* I don't currently have a current boot setup on the HDD. It is still Snow Leopard and I intend to keep it that way for various reasons. Win 7 really requires Bootcamp from Lion or newer.

If I can't solve this, I'm more likely to upgrade the old PC I have with a new GPU and connect it to the iMac, but right now native Windows boot support is not critical. A new game I'd really like to play might change that, but I have enough indie games on my plate for now, and there are Mac versions of things like Witcher 2 and Borderlands 1/2 that I might yet try.