When the data loss problem occurred:
My Lenovo laptop has both Windows 7 and Ubuntu 12.04. There are two ntfs partitions shared between the two OSes: one for Windows 7 installation ,and the other for personal data files.
Earlier today, when I was in Windows 7, I restarted the computer into Ubuntu. The ntfs data partition shared between Windows 7 and Ubuntu 12.04 was not able to automatically mounted, which is unlike usual, while The ntfs Windows installation partition was mounted automatically just like usual.
Then I restarted the computer back into Windows 7, and the ntfs data partition had been completely emptied, except leaving only one Windows system file
bootsqm.dat and one Windows system directory `System Volume Information. The time shown by Windows 7 has also been adjusted to be 4 hours in advance than the actual time. The ntfs Windows installation partition was still fine.
When I restarted the computer again into Ubuntu, same things as in the previous paragraph happened.
What happened before the problem occurred:
Right before my first reboot from Windows 7 to Ubuntu 12.04,
upon logging into Windows 7, there was some automatic configuration of Windows, which took two reboots and a couple of minutes to complete.
after logging into Windows 7, I installed some software (MathType and MikTex and LibreOffice), and edit some documents in Microsoft Office Word, and MathType (I got it from http://dl.portablesoft.org/down/?id=2515, which I originally thought was a trial version, but later I learned was a cracked version and felt wrong. I made a copy of it at dropbox http://dl.dropbox.com/u/13029929/MathType_6.8_PortableSoft.rar, not for distributing it but to list it there just in case it will help to identify the problem), and LibreOffice. De-select the autorun of some "message center" of Lenovo Toolkit when Windows starts each time.
Possible reasons and recovery solutions?
I got some suggestion from another person:
First tip is to look at your partition table. Windows is particular about the partition IDs and order of partitions in a way that Linux is not, and if it sees something it doesn't like, it will rewrite the partition table. Check the tables to see if they are in the same order as before you booted into Windows.
I wonder how to look at the partition table, and how to see whether Windows rewrite the partition table, and whether they are in the same order as before I booted into Windows?
Any other possible reasons and recovery solutions for the data loss? Can the cracked MathType be the reason?
When trying to make diagnosis and recover my data, which operating system shall I work under, Windows 7 or Ubuntu 12.04?
Thanks in advance!