grab linux distro ISO like for example ubuntu -> pendrivelinux.com/ or http://unetbootin.sourceforge.net/ for software to make bootable USB stick. Make sure the computer is set to boot from usb (which you should have done when trying to boot your external Windows drive) and boot the linux distro up. Use Gparted partitioning software (include with linux distro) to see if it recognizes the hard drive and all of it's partitions. If it doesn't recognize the Windows recovery partition, then more than likely your Windows Recovery options are gone. As an aside, your Windows recovery /installation files could also be corrupt. If drive and partitions are recognized then you can just reformat the Windows related partitions but not the Recovery Partition. If you want to reinstall Windows on that drive again, then see if you can boot into Recovery -> Install Windows via the installed drive or make sure that the computer is again set to boot from your Windows Install external drive. Be aware of any UEFI requirements too though the Windows installation should manage that aspect, iirc (been awhile since I played with that stuff). BTW, you can also do the Windows install from a prepared Windows Installation USB stick. See the following for example of the correct procedure:
Edit: Now I think about it, all Windows partitions except the Recovery Partition can just be deleted with GParted as Windows will recreate the correct partitions during installation. Someone please correct me if I am wrong on this; as mentioned previously it’s been quite a while since I last played around with Windows.
grab linux distro ISO like for example ubuntu -> pendrivelinux.com/ or http://unetbootin.sourceforge.net/ for software to make bootable USB stick. Make sure the computer is set to boot from usb (which you should have done when trying to boot your external Windows drive) and boot the linux distro up. Use Gparted partitioning software (include with linux distro) to see if it recognizes the hard drive and all of it's partitions. If it doesn't recognize the Windows recovery partition, then more than likely your Windows Recovery options are gone. As an aside, your Windows recovery /installation files could also be corrupt. If drive and partitions are recognized then you can just reformat the Windows partition (Not the Recovery Partition). If you want to reinstall Windows on that drive again, then see if you can boot into Recovery -> Install Windows via the installed driver or make sure that the computer is again set to boot from your Windows Install external drive. Be aware of any UEFI requirements too though the Windows installation should manage that aspect, iirc (been awhile since I played with that stuff). BTW, you can also do the Windows install from a prepared Windows Installation USB stick. See the following for example of the correct procedure:
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grab linux distro ISO like for example ubuntu -> pendrivelinux.com/ or http://unetbootin.sourceforge.net/ for software to make bootable USB stick. Make sure the computer is set to boot from usb (which you should have done when trying to boot your external Windows drive) and boot the linux distro up. Use Gparted partitioning software (include with linux distro) to see if it recognizes the hard drive and all of it's partitions. If it doesn't recognize the Windows recovery partition, then more than likely your Windows Recovery options are gone. As an aside, your Windows recovery /installation files could also be corrupt. If drive and partitions are recognized then you can just reformat the Windows related partitions but not the Recovery Partition. If you want to reinstall Windows on that drive again, then see if you can boot into Recovery -> Install Windows via the installed drive or make sure that the computer is again set to boot from your Windows Install external drive. Be aware of any UEFI requirements too though the Windows installation should manage that aspect, iirc (been awhile since I played with that stuff). BTW, you can also do the Windows install from a prepared Windows Installation USB stick. See the following for example of the correct procedure:
grab linux distro ISO like for example ubuntu -> pendrivelinux.com/ or http://unetbootin.sourceforge.net/ for software to make bootable USB stick. Make sure the computer is set to boot from usb (which you should have done when trying to boot your external Windows drive) and boot the linux distro up. Use Gparted partitioning software (include with linux distro) to see if it recognizes the hard drive and all of it's partitions. If it doesn't recognize the Windows recovery partition, then more than likely your Windows Recovery options are gone. As an aside, your Windows recovery /installation files could also be corrupt. If drive and partitions are recognized then you can just reformat the Windows partition (Not the Recovery Partition). If you want to reinstall Windows on that drive again, then see if you can boot into Recovery -> Install Windows via the installed driver or make sure that the computer is again set to boot from your Windows Install external drive. Be aware of any UEFI requirements too though the Windows installation should manage that aspect, iirc (been awhile since I played with that stuff). BTW, you can also do the Windows install from a prepared Windows Installation USB stick. See the following for example of the correct procedure:
https://www.microsoft.com/en-ca/software-download/windows10ISO