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I did a software update on my 64-bit Windows 8 and after restarting my computer, I no longer get my boot menu with Ubuntu 12.10, but instead get a black screen that says:

error: unknown filesystem.
grub rescue>

This is after running boot-repair, which gave me this link:

I really have no idea what to do. Thank you in advance for any response!

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have you tried changing the boot flag to your ubuntu partition? you can do that through a live CD using gparted, select the linux partition, right click then "manage flags" and check the boot flag. – Sam Nov 19 '12 at 2:34
didn't work. The windows partition has a red (!) next to it when I looked at its information, it says cluster accounting failed at (0x4d13e2): extra cluster in $Bitmap. It is the same error two more times for (0x4d13e3) and (0x4d13e4). It says ERROR: NTFS is inconsistent. Run chkdsk /f on windows then reboot twice. I can't even boot into Windows... – Jose Vergara Nov 19 '12 at 5:00
Don't move the boot flag, it is correctly set. – LovinBuntu Nov 19 '12 at 10:56
  1. Use a Windows disk this way: , until you get direct access to Windows
  2. Then use Boot-Repair to recover your GRUB menu.
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