Mac stopped booting after removing bootcamp partition

Bootcamp is a Mac utility which helps to run Mac OS X and windows both on your Mac machine. This utility will create partition on your Mac hard drive and install Windows on your Mac. But, you would have read many problems shared by Mac users in various forums related to bootcamp. One of my friends stumbled onto some problems with Mac after removing the bootcamp partition. I am desribing the way we fixed the issue and hope the discussion would help many other Mac users facing this sort of problem.

My friend was not using Windows since last month so, he decided to delete the partition and gain some more hard drive space. He just browse to the utility folder in Mac and start up the bootcamp application to delete the partition and reclaim Mac hard drive space. I have done this many times with my Mac and it worked flawlessly. But, this time it didn't work on my friend's Mac machine.

There was some problem in booting process, which we were trying to fix. We connected the drive externally with another healthy machine. The drive got detected but can't be initialized. We tried another solution to get rid of this issue and got a third party tool i.e TestDisk online, this application was good , it can easily read the hard drive and enable message to apply the correct partition table without damaging anything. After using this tool we could easily boot our Mac.