If a hardisk is connected via USB to Windows and I attempt to open it, Windows says it needs to be formatted before it can be used. If I ignore this message and run disk wipe on it (like the cipher command line tool from Microsoft), will it work? Or will the lack of formatting mean that not everything will be wiped?
2 Answers
Apparently cipher is a program the fill the unused space of a filesystem (by writing a file of random data that takes up all of that, I assume), so no, you can't get a block of the partition / disk overwritten with the program if it isn't considered "recognizably formatted" / a mountable volume by Windows.
If you really want to zero-fill every block of a disk, use clean all and diskpart.
If you want to on block-level zero-fill only a partition (so that you can keep the partition table, and maybe data on other partitions or the gaps, if any, in between), or random-fill instead, consider programs available in Cygwin / msys2, e.g. dd, shred or even openssl enc. (I'm not exactly a "keen" Windows user so I don't have "native" equivalence in my knowledge.)
For wiping purposes you can ignore that message. To wipe a hard drive you don't need a formated partition on it. Once you have full access to the drive you just use a wiping program that is overwritting sector by sector. After reading the description of the "cipher" command in Windows 7 I do not consider this as a wiping tool.
The security of wipe actions like "ATA Security Ease" depend on its implementation. when dealing with solid state drives it provides a certain hope that triggering that action might reach and wipe storage that your computer has no access to.
As for your comment:
The cipher has a /w switch to wipe so I think it works.
No that is just a partly wipe with one partition of a disk. This is far away from "disk wiping".
disk wipethough