As described in another post, in summer 2014 TrueCrypt was in the throes of a major change and/or its demise. Awkwardly, TrueCrypt had also just received a passing grade on the first phase of an in-depth audit of its security capabilities, and meanwhile DiskCryptor, possibly its chief competitor, was still showing definite signs of immaturity. My working solution under these circumstances was to retain TrueCrypt (using version 7.1a, which as noted in that other post was still available for download, not version 7.2) and simultaneously to work toward greater familiarity with DiskCryptor.
The event triggering my inquiry had been simple and familiar. In TrueCrypt 7.1a, I had encrypted a hard disk drive (HDD) with a set of options that yielded a problematic error message, each time I connected the drive. This was an internal type of hard disk drive (HDD), but I was using it as an external drive: I plugged it into an external drive dock, connected to the computer via USB cable, and turned on the power. Shortly after I did that, Windows popped up a dialog that said this:
You need to format the disk in drive F: before you can use it.
Do you want to format it?
I knew better than to click Yes. And yet, came the day when I was not paying attention, and clicking Yes resulted in the loss of the data on that drive.
Next time I used TrueCrypt to encrypt a drive, I would want to arrange things so that it would not pop up that Windows dialog. To achieve that result, people suggested several approaches, including these:
- Use a partition manager (e.g., Disk Management or, for a friendlier option, MiniTool Partition Wizard or Easeus Partition Master or Parted Magic) to divide the drive into a tiny partition and a large partition. The sole purpose of the tiny partition is to be formatted as NTFS so that Windows will recognize it as a drive. This will apparently eliminate the error message. Now use TrueCrypt to encrypt the large partition as desired.
- Instead of using TrueCrypt to encrypt an entire partition, use TrueCrypt to create an encrypted file filling a Windows-formatted partition.
- Use TrueCrypt to encrypt the entire drive. Then use the Windows diskpart tool to change the drive type. That is, at the Windows command prompt, type diskpart and then enter this sequence of diskpart commands: list disk, select disk N, list partition, select partition N, set id=64, exit. With this approach, the partition will no longer be recognized as a TrueCrypt favorite. That will not matter to people who do not use favorite names in TrueCrypt.
- In Disk Management (diskmgmt.msc), right-click the TrueCrypt partition > Change Drive Letter and Paths > Remove. This approach would reportedly work only on the machine on which it was done; connecting the drive to another computer would apparently produce the “You need to format the disk” message.
I tried approach no. 1. It did not work for me. I did not try no. 2. I tried no. 3. In my case, disk N was disk 6. When I typed “set id=64,” I got back, “DiskPart successfully set the partition ID.” I exited diskpart, unplugged the drive, reconnected it — and, what do you know, it worked. This time, no pop-up offering to reformat the drive. I went into TrueCrypt and mounted the drive. Everything seemed good. It appeared that option 3 worked for me.