Ubuntu installer doesn't recognize windows installation

[bJob]

Hello everyone
yesterday I tried to dual boot windows and ubuntu.
But the ubuntu installer (windows was installed first) only shows 2 options earase hwole drive and install ubuntu or choose manualy (sorry but I forgot the English name for this thing) I clicked the second thing and the intaller only shows My 1tb hard drive as an unformated drive with no partitions.
Please help me.

Thanks.





Sorry for my crappy English.(I speak dutch)

[garvinrick4]

Is it a basic drive or dynamic drive?

[zeroseven0183]

Which version of Ubuntu are you trying to install? Please give us more information.

Here's the link to dual booting Ubuntu and Windows to guide you. https://help.ubuntu.com/community/WindowsDualBoot

[bJob]

These are my Hard drives specs

[Mark Phelps]

If you're running Win7, you could try the following:
1) Boot into Win7, use the Disk Management feature to shrink the Win7 OS partition to make some room for Ubuntu.
2) Reboot, but using the Ubuntu CD.

NOW, see if Ubuntu can see the unformatted space.

IF it can, you can install to that space and let the installer format it. Just don't allow the installer to shrink your Windows install.

Also, BEFORE you do that, would be a good idea to boot into Win7 and use the Backup feature to create and burn a Win7 Repair CD. That will come in handy later, should you need to repair the Win7 boot loader or restore the original MBR.

[YesWeCan]

Hi. If the Ubuntu installer sees no partitions on your Windows drive then something is obviously wrong. There are a few things that can cause this. For example, if your disk has a GPT header on it or if it has dmraid superblocks.

First, would you post the output of:
sudo sfdisk -luM

[bJob]

Hi. If the Ubuntu installer sees no partitions on your Windows drive then something is obviously wrong. There are a few things that can cause this. For example, if your disk has a GPT header on it or if it has dmraid superblocks.

First, would you post the output of:
sudo sfdisk -luM

Here are the results


WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util sfdisk doesn't support GPT. Use GNU Parted.


Disk /dev/sda: 121601 cylinders, 255 heads, 63 sectors/track
Units = mebibytes of 1048576 bytes, blocks of 1024 bytes, counting from 0

Device Boot Start End MiB #blocks Id System
/dev/sda1 * 1 100 100 102400 7 HPFS/NTFS
/dev/sda2 101 953866 953766 976656384 7 HPFS/NTFS
/dev/sda3 0 - 0 0 0 Empty
/dev/sda4 0 - 0 0 0 Empty

Disk /dev/sdb: 487 cylinders, 255 heads, 63 sectors/track
Units = mebibytes of 1048576 bytes, blocks of 1024 bytes, counting from 0

Device Boot Start End MiB #blocks Id System
/dev/sdb1 * 0+ 3820- 3821- 3911796 c W95 FAT32 (LBA)
/dev/sdb2 0 - 0 0 0 Empty
/dev/sdb3 0 - 0 0 0 Empty
/dev/sdb4 0 - 0 0 0 Empty

[YesWeCan]

Wow - really GREEN!

Yes, the issue is that your drive has a GPT format header on it and you need to remove it. Windows does not use it, it uses the MBR format and ignores the GPT header but the Ubuntu installer gets confused.

Run EXACTLY this command, copy & paste it. If you make a typo you could trash your Windows installation.

sudo dd if=/dev/zero bs=512 count=1 seek=1 of=/dev/sda

Then try the Ubuntu installer again.

[srs5694]

Here are the results


WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util sfdisk doesn't support GPT. Use GNU Parted.

The green text makes that hard to read. For future reference, when posting output from text-mode programs, it's best to:

• Leave the color scheme alone.
• Start the text you've cut-and-pasted with a [code] tag and end it with a [/code] tag. This preserves column alignment and improves legibility.

Yes, the issue is that your drive has a GPT format header on it and you need to remove it. Windows does not use it, it uses the MBR format and ignores the GPT header but the Ubuntu installer gets confused.

Run EXACTLY this command, copy & paste it. If you make a typo you could trash your Windows installation.

sudo dd if=/dev/zero bs=512 count=1 seek=1 of=/dev/sda

Then try the Ubuntu installer again.

YesWeCan's analysis is correct, but the command he recommends does only half the job. GPT includes, by design, both primary and backup data, the primary being at the end of the disk and the backup being at the end of the disk. The dd command that YesWeCan recommends only deletes the primary GPT header, leaving the backup GPT header in place. Under some circumstances, this can result in problems down the line, since some utilities do check for backup GPT data and it's conceivable that its presence will cause confusion.

There are several ways to deal with this, but the simplest and safest, AFAIK, is to run my FixParts utility, which will delete both the primary and the backup GPT headers. Unfortunately, FixParts isn't yet included with Ubuntu, so you'll need to download it (here's a download matrix for several distributions) or run it from an emergency disc such as PartedMagic, which includes the tool.

[bJob]

so ubuntu is installed now but grub doesn't load and the computer boots automatically in to windows.