[ubuntu-za] Can't Boot after Windows 10 upgrade

[wesley werner]

On 09/02/2016 14:18, Robin Bownes wrote:
> On 9 Feb 2016 13:08, "Robin Bownes"
> <<mailto:robin at bownes.co.za>robin at bownes.co.za> wrote:
>  >
>  > Apparently, from some reading I've done - which unfortunately didn't
> give me anything I felt confident trying to do - the Windows upgrade
> overwrites part of the partition table, but not the contents of the
> partition. That is why the previously Linux partition now shows up as
> "unknown".
>  >
>  >
> So the partition is still mountable from a live disk then?

Hello Robin

That is possible assuming the data is still intact. The trick is finding 
out which partition contained Ubuntu:


Model: ATA WDC WD3200BEKT-7 (scsi)
Disk /dev/sda: 320GB
Number  Start   End     Size    Type      File system     Flags
1      1049kB  5692MB  5691MB  primary   ntfs            diag
2      5692MB  65.3GB  59.6GB  primary
3      65.3GB  65.8GB  472MB   primary   ntfs            boot, diag
4      65.8GB  320GB   254GB   extended
5      316GB   320GB   4082MB  logical   linux-swap(v1)


Partitions #1 and #3 seem to be for windows recovery, #2 windows itself, 
and #5 the Ubuntu swap.

The discrepancy I notice is that partition #4 reserves 254GB (extended 
partitions are not real partitions but a grouping of other partitions), 
of which only 4GB is allocated to the swap. There is 250GB not allocated.

I dare to say there used to be a partition #6 that was 250GB and 
contained Ubuntu, but why it would have been removed is beyond me, and 
why the swap was left intact even more so!

Since that space is unallocated it will (to your luck) not be written 
into, the data might still exist. As a last resort you can use fdisk or 
gparted to re-create partition #6 using the unallocated space, and try 
mount it. Assuming there was a #6 and it used the rest of the 
unallocated space, and windows did not resize it into itself in some part.

There are various other partition recovery methods mentioned online and 
you might try those before re-creating the partition as I mentioned 
above, but recovery is at the very least a complex task.

Wesley