This project has moved and is read-only. For the latest updates, please go here.

"Host file/device already in use"


Using 1.15 under Win7 fully updated, I am trying to mount a device (the whole drive has been encrypted with an earlier version of VeraCrypt), I keep getting the message the the host file/device is already in use. It isn't. No drive letter has been assigned etc.

I get this message when I try to mount a different drive similarly encrypted with an earlier version of Vera Crypt.

One of the drives is plugged into a SATA slot, the other is a USB drive. I'm a long term user of TC and have been with VC from early days and so I like to think I know what I am doing, but... is there something I'm doing wrong?

Many thanks.


idrassi wrote Oct 6, 2015 at 3:44 PM

Can you please try with the 1.16-BETA available here:

The TrueCrypt vulnerabilities patch implemented in 1.15 introduced many side effects on Windows and version 1.16 will bring a more stable fix.


xrTx wrote Oct 7, 2015 at 1:51 PM

I tried using 1.16-BETA but had the same warning - 'file/device is already in use'. Even if I ignore the warning and press, "Yes" to continue mounting, I get a second message saying "Error: Cannot mount volume. The host file/device is already in use. Attempt to mount without exclusive access failed as well."

I'll revert to an earlier version, to see if that works for now. Let me know if you want me to try something else.


xrTx wrote Oct 7, 2015 at 2:49 PM

I tried downgrading to 1.0f-2 and am getting the same problem. Is it possible that residual files are left on the system and not downgraded? The reason I say this is if I plug the same drive into another computer running VC1.12 (and which has not been upgraded), I can access the drive okay.

Enigma2Illusion wrote Oct 7, 2015 at 3:42 PM

You might try installing Windows Sysinternals Process Explorer to see which program has a particular file or directory open.

Which Anti-Virus are you running on the PC that is giving the error?

xrTx wrote Oct 7, 2015 at 4:10 PM

The device is not mounted by the OS so there are no files to access/lock. The whole device was encrypted by VC - that is there is not even a partition as such.