How do I recover my (potentially) ruined (600+GB) Windows installation?

Question

I was installing Xubuntu onto the same hard disk that my huge installation of Windows was on and I accidentally pressed "Okay" after I chose to do my own partitioning. The last thing I saw before I did a hard shutdown was something about EXT4 partition tables. Is there a way to fix my (600+ GB) Windows 7 install to booting again so I don't have to redownload and reinstall all my stuff?

I just booted the live USB I screwed my intallation with and it lists the Windows 7 partition as "xubuntu". "xubuntu" has a filesystem called "lvm2 pv". Am I screwed or can I change it back to whatever Windows uses without losing data?

@VRU If I boot to the hard disk: A blinking line, as if there is no OS installed. — tomburnes, Jan 10 '13 at 11:29
I had (have hopefully?) over sixty steam games on that drive(!) — tomburnes, Jan 10 '13 at 11:31
As you have not written anything to the drive but partition tables you will very likely be able to recover all of your partitions with TestDisk but stop using the drive. Any write access to the drive will reduce the chances to recover all. — Takkat, Jan 10 '13 at 15:37

score 0 · Answer 1 · answered Jan 10 '13 at 11:53

Unfortuantely, it would seem you are boned. From what little I understand about partitioning and the wiki article regarding ext4, the Xubuntu boot was in the process of wiping your partitions and creating its own. This does not, however, mean necessarily that the files are lost, but certainly enough information was changed or lost that the computer no longer recognizes how to boot the drive.
You can try removing the drive and, if you have a hard drive enclosure, a universal usb drive adaptor, or some other way of hooking up your PC's hard drive to a different and functioning computer. With any luck, your drive will appear just as any other external hard drive would and you may be able to access some if not most of your files. If it does not, or most of the files don't appear within the drive, there are various free and costly softwares available to attempt to recover the lost data.
Link: http://en.wikipedia.org/wiki/List_of_data_recovery_software
This above link offers a multitude of software. Barring any of these working your only remaining option would be an even more expensive professional recovery which carries 0 guarantee of success.

Fortunately, once you get your system up and running again, steam can re-download and reinstall all of your games. Though accessing your steam account from a "new" computer may be your biggest obstacle here.

Hope this helps and best of luck.

I doubt this will work but I am trying "boot-repair" [https://help.ubuntu.com/community/Boot-Repair] — tomburnes, Jan 10 '13 at 12:01
Your problem is loss of data / partition table. Boot-Repair will not help for this, use TestDisk instead. — LovinBuntu, Jan 12 '13 at 06:44

score 0 · Answer 2 · answered Jan 10 '13 at 13:25

Unmount the partition and don't use write to it at all! Then make a backup with cat or dd:

dd if=/dev/sda of=backup.iso

Once you've made a backup, then you can try and recover the data without risk of further ruining the drive. Here is a guide to data recovery in Ubuntu (but it's the same idea for other distributions)

As for steam games, are they not synced with your account?

How do I recover my (potentially) ruined (600+GB) Windows installation?

2 Answers2