Defraggler has crashed twice now, is this going to break my drive?

Defraggler has crashed twice now, giving the classic Win7 error message "this program has stopped working". The first time was during a defrag because I clicked the 'minimize' button, but luckily my drive was fine afterwards. The second time was after clicking 'ok' in the options dialog. The only programs running in the background were various system processes, and Firefox.

I'm worried this is going to break my hard drive. I recall a long time ago, I ran a boot defrag on an old NTFS drive in WinXP. There was a power failiure, and it just so happened to be while the defrag software was writing the Master File Table. It took raw harddrive data viewing software to find the backup MFT in the middle of the drive, as well as Seagate's MFT editing software, to get the drive working again.

Are these crashes during defragging likely to break my drive?

Are these crashes during defragging likely to break my drive?

No, they just stop the defrag process, which you can restart later. I suggest you shut down all unnecessary programs during defrag, like FF.