I recently deleted the partition on an external USB Drive. I have always been cautious when I install Operating Systems. But this time I accidentally left my backup USB hard drive (1TB !) plugged in when I tried reinstalling Windows XP on one of my old desktop. I was I have only one hard drive but 2 partitions showed up during the installation. And I wasn't thinking when I deleted both of them. But moments after I deleted both of my partitions - 1) My internal hard drive partition and 2)My external USB drive partition I had the "ah hah" moment!!! Yes I realized before I did format my drives so I immediately quit the setup.

Then I tried plugging in my hard drive into another XP machine which said it was an unformatted drive and asked me whether I want to format. Luckily I said "No" and when the logical place anyone would go to find a solution. You guessed it right - Google. Thanks to Google, I had to spend the next few minutes searching for different options. I tried using dskprobe.exe from Windows Support Tools but not much luck - it is a low level tool even though it is GUI based tool. Then I tried Partition Magic - which didn't give me the option to undelete the partition I deleted. I have heard stories about people paying thousands of $$$ for disk recovery. Some the information on that 1TB external USB drive are not very important but my pictures and other backups are very important for me. So I continued to stay in "Panic Mode" for few more minutes until I found a forum thread discussing about TestDisk - which is an OpenSource software (http://www.cgsecurity.org/wiki/TestDisk).

The tools is a command-line based tool but very helpful and has detailed documentation that helped me. It took sometime as I had to search for the partition through the entire 1TB space. But that tool couldn't find the partition. The tool extrapolated the boot sector as the boot sector was not present my hard drive and also the back up boot sector was not present. Finally I am able to access my files on that 1TB hard drive now. Lesson learned - Always take extra care when you install and uninstall software!!! And think thrice before you delete anything!!!