cgsecurity.org

Hi, this isn´t my first time using testdisk, and I´m really happy with the software, but I have a problem...., I´m trying to recover a fat partition that has been refomated, in this case I´m using an image of the hard disk, mounting it with osfdisk, everytime is working great until i have to rebuild the BS, I´m trying TestDisk / Advanced / Boot and RebuildBS, but as soon as it starts I get a blue screen saying system thread exception not handled, and the process causing it´s osfdisk.sys,
I really need to recover the partition, any help? please?