bootable-diskbootcamphard driveimacwindows
I had a windows laptop that bit the dust, but the hard drive works fine (booted up in another pc that wasn't mine as an external disk with my SATA to USB 3 adapter).
I'd like to use this drive on my iMac (2011 27 inch) without reformatting it and without having to go out and buy a new windows license key. Is there a way I could use the existing and functional license in boot camp, or better yet boot the OS from the drive?
If you get a copy of Paragon NTFS for Mac you can do a disk repair for NTFS volumes. The software has a 10 day trial and a license is about $20. NTFS for Mac also serves as a driver for full access to NTFS volumes which is superior to the limited Read only access of NTFS volumes built into Macs. If you are a regular user of both Mac and Windows its worth the investment.
Once installed the program is accessible from System Preferences. For the problem described above you need to first unmount the volumes "System Reserve" and "BootCamp". Then remount the volumes and run verify on each volume.
Have you opened Disk Utility and tried to format it already? Sometimes a drive will not appear on the desktop, but will appear in Disk Utility.
I've had windows drives show up sometimes, and not other times. What you could do to make it more likely to show up is go to an available (hopefully not too difficult) windows machine and reformat the drive as a FAT/MS-DOS drive (don't do quick-format). This should be easier for the mac to see.
Once you can see the blank FAT formatted drive, open Disk Utility and then select it on the left sidebar and erase it again as a "Mac OS Extended (Journaled)" (HFS+) format.
There are other methods like using an emulation environment like Parallels Desktop (IMHO bad SW company), VMWare Fusion (my choice), or VirtualBox (free) (all of these require a windows install disc); or you could even try using programs like MacFuse or NTFS-3G, Tuxera, etc., to mount windows (NTFS) drives directly in the Finder. But unless a mac you can find has one of these solutions, it's probably not worth it to go through the trouble just to erase one drive.
Lastly, I've also had some external USB enclosures not show up on some versions of OS X! So the cheapy enclosure you got just might not work with your installation anyway?
Details that might be helpful for potential helpers:
HD interface PATA/ATA/IDE or SATA?
OS X Version?
iMac model year or identifier?
Enclosure is assumed to be USB 2.0 high speed plugged into built-in port on iMac. Correct if wrong.
Best Answer
Windows licenses, unlike Mac, do not belong to the person but to the machine. They are not transferrable between machines.
Sometimes just changing a hard drive or graphics card would be enough to trigger the 'you appear to be using a different computer' warning, needing you to ring Microsoft to re-authorise.
So, aside from any actual surmountable issues of persuading Windows to run from an external drive [which only Windows 10 will do, iirc] or setting up a fresh Boot Camp partition then making a bare-metal backup/restore to it using Acronis [the only software I know of that can move a Windows install between different physical hardware & still have it arrive in a bootable state] - once it arrives it will not be licensed.
You could, I suppose, at that point buy a new license.