Unisnstall a Linux installation or change boot order

[desposti]

Hello,
I have 2 huge disks and the following OS installed: Windows7, ubuntu 11.04 and recently installed12:04.
I deleted the partition where 12:04 was installed and I could not boot , gave me a grub error.
I had to reinstall and I am back to the problem : how can I safely uninstall Ubuntu 12:04 on sdb4 please?
Since I have a huge disk I max just consider changing the boot order because Ubuntu 12:04 is now first in order and I do not really use it, it was installed just for testing.
This is my fdisk -l output

Disk /dev/sda: 750.2 GB, 750156374016 bytes
255 heads, 63 sectors/track, 91201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x2189b0f5

Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 203776 7 HPFS/NTFS
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 88558 711135232 7 HPFS/NTFS
/dev/sda3 88558 91189 21128192 7 HPFS/NTFS
/dev/sda4 91189 91202 105336 c W95 FAT32 (LBA)

Disk /dev/sdb: 750.2 GB, 750156374016 bytes
255 heads, 63 sectors/track, 91201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x160ec3b7

Device Boot Start End Blocks Id System
/dev/sdb1 1 3188 25600000 83 Linux
/dev/sdb2 3188 5610 19456000 82 Linux swap / Solaris
/dev/sdb3 5610 87949 661391360 83 Linux
/dev/sdb4 87949 91202 26125312 83 Linux
diego@diego-HP-ENVY-17:~$

Thank you very much

[drs305]

Boot into your 11.04 Ubuntu and run the following. Use the drive your BIOS looks at first (sda or sdb). Don't use the partition number.

sudo grub-install /dev/sdX
This will return control to 11.04 and put it first in the boot order.

Once you confirm it's booting 11.04 as the default you can do what you want with the other Ubuntu's partition.

[darkod]

First of all, you didn't had to reinstall. You could have booted into live mode with a 11.04 CD and install grub2 to the MBR which would be connected to your 11.04.

So, what is that you want to do? Keep 11.04 and windows?

In that case, simply boot the 11.04 and in terminal do:
sudo grub-install /dev/sdb

That will install your 11.04 grub2 on the MBR of /dev/sdb. Set in bios to boot from sdb and that's it.

After that you can delete the 12.04 partitions you don't need. Note that 11.04 will run out of support soon, so you better start thinking about using a LTS version like 12.04.

If the 12.04 still exists in the grub2 menu of 11.04 after deleting the partition, to update grub2 run:
sudo update-grub

[desposti]

First of all, you didn't had to reinstall. You could have booted into live mode with a 11.04 CD and install grub2 to the MBR which would be connected to your 11.04.

So, what is that you want to do? Keep 11.04 and windows?

In that case, simply boot the 11.04 and in terminal do:
sudo grub-install /dev/sdb

That will install your 11.04 grub2 on the MBR of /dev/sdb. Set in bios to boot from sdb and that's it.

After that you can delete the 12.04 partitions you don't need. Note that 11.04 will run out of support soon, so you better start thinking about using a LTS version like 12.04.

If the 12.04 still exists in the grub2 menu of 11.04 after deleting the partition, to update grub2 run:
sudo update-grub


Thanks . I did it but still doesn't look that 11.04 is the default or on top of the list. Nothing seem changed. I am a bit scared of deleting 12.04 in case I have the boot error again

[drs305]

Thanks . I did it but still doesn't look that 11.04 is the default or on top of the list. Nothing seem changed. I am a bit scared of deleting 12.04 in case I have the boot error again

Is your BIOS booting sdb first? If it is booting sda first, you would want to run the grub-install command using sda. Or you can change the BIOS to boot sdb first.

However, if you set up grub so the Windows bootloader was still on sda (but not used because the system is booting off sdb), don't do the grub-install /dev/sda yet.

You might want to try the Boot Repair app. There is a link in my signature line. Install and run it from your 11.04 system.

[desposti]

Is your BIOS booting sdb first? If it is booting sda first, you would want to run the grub-install command using sda. Or you can change the BIOS to boot sdb first.

However, if you set up grub so the Windows bootloader was still on sda (but not used because the system is booting off sdb), don't do the grub-install /dev/sda yet.

You might want to try the Boot Repair app. There is a link in my signature line. Install and run it from your 11.04 system.

Thank you. I tried the boot repair but gave an error. I restarted and I think nothing has changed. I am going to bed now but thanve ks for the quick reply. I think I will have to install 12.04 as main anyway sooner or later so I will live with this boot order and then when I install 12.04 on the big partition I will be able to delete the other one I guess.

Thanks