HDD loses USB 2.0 when it encounters bad sector
I have an external Cavalry 500GB 3.5" USB 2.0 HDD which recently started giving drive errors while trying to read a file which is very important to me (a disk archive image).
I bought a program, HDD Regenerator, to see if I could recover the sector, whose number I was able to identify. However, every time HDD Regenerator comes to this sector in its scan my HDD loses its USB 2.0 connection to the computer momentarily, then comes back up after a few seconds. This causes HDD Regenerator to mark all subsequent sectors as bad and unrecoverable, which I know to be incorrect due to running HDD Regen slightly after the known bad sector.
So, do you know why the HDD would lose and regain the USB 2.0 connection like this, and is there any way to prevent this from happening?