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I just bought a new ASUS computer with WINDOWS 8 pre-installed (so UEFI and secure boot activated) and it is no more working since I did a mistake with GDISK:

I wanted to install UBUNTU alongside Windows8 in UEFI mode, but the option did not appear in the Ubuntu installer ("install ubuntu alongside Windows").

So I decided (bad decision I suppose) to use GDISK in expert mode (x option), and I did "z" option: "zap (destroy) GPT data structures and exit"

by hoping I will have the "install alongside Windows" option in the installer.

And now, each time I start computer, the BIOS (UEFI) appears, and the PC block on it, Windows 8 no more starts.

Please can you give me a solution to restore GPT partiton table?

Thank you in advance.


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up vote 1 down vote accepted

The z option in gdisk completely destroys the partition table, so you effectively no longer have your Windows installation. I know of at least four solutions to this problem:

  • Call the manufacturer, get a Windows restore disk, and restore the system to the factory default.
  • Obtain a Windows retail disk and install it to your computer.
  • Use TestDisk or some similar tool to recover your lost partitions. You may need to then run a Windows emergency tool to make the computer boot to Windows.
  • Install Ubuntu to the blank disk and forget about Windows.

After any of these options, you can try again with your Ubuntu installation, but you'll probably need to use the "Something Else" option if you want to dual-boot with Windows, since most (all?) people who've tried it report that "Install Alongside" doesn't work on GPT disks.

Note that the first two options will leave you with a fresh Windows installation. If you have user data files on the disk, you should favor the third option, or try to recover your personal data files before proceeding with either of the first two options.

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Another possible option. One user posted that the retailer he bought system from, still had same model on shelf. Tech made the recovery set of DVDs for the user. Not sure many retailers would do that, but it was good customer service. – oldfred Jul 14 '14 at 20:06
Great answer, which solves my problem! My computer has been restored to Windows 8.1! I run TestDisk in order to recover my partitions. Then, i fix the windows boot loader by launching the USB recovery media, and using the diskpart, bootrec and bcdboot microsoft utilities as described in this tutorial… – user2398640 Jul 14 '14 at 22:06
Ok Now my computer starts under Windows 8, I would like to install Ubuntu in DUAL BOOT. I did a "fixpart" in order to zap the GPT as decribed here…. I install Ubuntu successfully, but now it starts still automaticcally with Windows 8 and does not allow me to choose between Windows or Ubuntu. Any suggestion? – user2398640 Jul 15 '14 at 13:26
I recommend you search on your current symptoms or start a new question, since it's not clear what the current status is, but it's almost certainly not very close to what you describe in your original question. – Rod Smith Jul 15 '14 at 14:27

Did you deleted windows 8 (C drive) Partion ?

Boot for ubuntu live cd and make sure you din't delete c drive, if you done so most probably your grub is messed.

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