If the drive disconnects during a write operation, then most likely you have a problem with the enclosure's interface module, given the fact (apparently) that you "toasted" several drives with it. That is a little different than a drive dismounting while idle, which is what the majority of the posts in this thread (including mine) seem to be talking about. In many cases where the drive dismounts while it is not idle, the drive mechanisms themselves are OK, but their directory structure gets corrupted due to the disconnect. This has long been an issue with FireWire drives, for example, when an owner either disconnects it without first dismounting or simply removes power. This also happened with an old MyBook enclosure I had, due to the failure of the enclosure's temperature monitoring feature, which lead to disconnects in the middle of write operations. The WD Blue drive mechanism in it, however, was still good. Most of the work was extracting it from the stupid WD proprietary enclosure, which is built to keep meddlesome customers out. I strongly suggest you try a different enclosure (the NewerTech Voyager one costs $40) or one of those Swiss Army Knife interface gizmos (maybe even cheaper - I paid $20 for a no-name one) and see if you can use the Apple Disk Utility or a third party application (e.g. Drive Genius, etc.) to be able to do something with your drives. Disk Utility may still detect the drive, even if corruption prevents it from being mounted. Likewise with the Windows Storage Manager, which you will find if you right click on "My Computer" and select "Manage." You may be able to run a repair to recover the data or, if that fails, it may allow you to reformat your drives so they become useful again.