Does running two different hard drive recovery softwares (Recuva, TestDisk etc) hamper any chances of data recovery. Its probably not as I don't think they'd be doing any writing at all. But just to be sure, does it reduce my chances of recovery at all?
It may not, but you're going to thrash the drive with the constant reads and in turn will slow both pieces of software down. Why not try one, then the other?