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I have many computers encrypted with Truecrypt 7.1a (current version) with the whole drive encrypted. Today one of them shows the Windows 7 splash screen for a moment and then goes into startup repair which can't read the encrypted drive. I've tried the various safe modes and what not.

The solution is to decrypt the drive and then run startup repair to fix the drive. The problem is that is going to take 50 hours. I've started that process for this situation but I need to have a way to cover myself when this happens to the next PC.

What can I do to avoid decrypting the whole drive? I can't be the only one facing this problem so I feel like I must be missing something.


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60 hours later the 500 GB drive finished decrypting. I launched Windows Startup repair and the problem was fixed in 5 minutes. I've got to be missing something here and I imagine I'm not alone. – PHLiGHT Jun 28 '13 at 19:08
I just booted a working Windows 7 laptop that was encrypted the same way with UBCD4Win. I ran Truecrypt portable and am able to access the drive. What does Windows 7 startup repair do and how can I run it on the drive in this environment (UBCD)? – PHLiGHT Jul 3 '13 at 19:03
I would really like to know the answer to PHLiGHT's last comment. How can I run Windows 7 repair from within another OS (like UBCD4Win). I've got my encrypted system drive mounted and can access the entire contents but I don't want to decrypt my 1TB drive. – John Aug 30 '13 at 6:53
up vote 2 down vote accepted

If you're quick enough, you can hit the [F8] button immediately after pressing Enter (after entering your TrueCrypt password) and it will give you the ability to repair your computer or enter any of the safe modes, etc.

Just verified it using Windows 7 Professional and TrueCrypt 7.1.

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Thanks, what a simple fix. Welcome to the community I appreciate you signing up to contribute this! – PHLiGHT Feb 25 '14 at 13:39
I got to the menu in my case but repairing doesn't detect anything. It doesn't detect the OS and when I run chkdsk /f/r on the c drive from the command line it tells me the disk format is RAW... – David Brossard Jan 10 '15 at 12:13

If Windows is damaged and cannot start, [...]

Note: Alternatively, if Windows is damaged (cannot start) and you need to repair it (or access files on it), you can avoid decrypting the system partition/drive by following these steps: Boot another operating system, run TrueCrypt, click Select Device, select the affected system partition, select System > Mount Without Pre-Boot Authentication, enter your pre-boot-authentication password and click OK. The partition will be mounted as a regular TrueCrypt volume (data will be on-the-fly decrypted/encrypted in RAM on access, as usual).

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That didn't work for me. I went as far as removing the drive from the computer to try that with no luck. – PHLiGHT Jun 28 '13 at 19:07
@PHLiGHT: That is supposed to be right procedure. Please let us know what didn't work, how far along did you get in the above procedure and whether you are sure that you used the right password. – harrymc Jun 29 '13 at 20:00
I had the right password since I was able to get it to get past truecrypt when then HDD was in the laptop. When I took it out and tried to access it on another PC (mounted w/o preboot authentication) the password wouldn't work. In Windows repair it stated it couldn't load some HP file on the X:\ but there isn't typically and X:\ when using the PC in Windows. – PHLiGHT Jul 2 '13 at 12:09
I can use this to gain access to the drive contents but how can I repair THAT Windows installation? – John Aug 31 '13 at 3:56

You can partition the 500gb disk to 50gb system partition or something like that, then you just have to decrypt 50gb(only the system disk/partition).

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You should have access to the Truecrypt portal that will give you a master key for that HD.

Take take the HD out of current workstation and use it on different workstation.

Unlock it with the key and repair.

*Intel i-series can make a critical issues with encrypting software.

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I can use this to gain access to the drive contents but how can I repair THAT Windows installation? – John Aug 31 '13 at 3:57
Try to get data off, and re-image the workstation. Last week we had a similar situation but we couldn't do anything because every single file was corrupted. – itmilos Sep 1 '13 at 15:20

The problem you are encountering with using from another computer the Select Device command with "Mount Without Pre-Boot Authentication" might be a bug in the latest version 7.1 of TrueCrypt.

From TrueCrypt Forums Accessing TrueCrypt-encrypted System Volume while Connected Externally :

Known Issues

Affects: TrueCrypt 7.1 for Windows

Issue: Volumes cannot be mounted by selecting System > Mount Without Pre-Boot Authentication.

Workaround: Until this bug is fixed, you can work around it by following these steps:

  • Click Mount.
  • Click Mount Options
  • Enable "Mount partition using system encryption without pre-boot authentication"
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I wasn't aware of this bug but I tried it both ways before w/o any success. – PHLiGHT Jul 3 '13 at 14:37
It seems this bug is new in TrueCrypt 7.1. You could try an earlier version (or wait for the fix to be released). – harrymc Jul 3 '13 at 16:08
I can use this to gain access to the drive contents but how can I repair THAT Windows installation? – John Aug 31 '13 at 3:58

The [F8] trick did not work for me and neither did Startup Repair but this was a one line fix to be able to boot again:

bcdboot c:\Windows /l en-us /s c:

I feel strongly that this would work before decrypting, but since I had already decrypted before finding this command, I don't know for sure. It took 2 days for researching via a phone, backing up the drive, then permanently decrypting via Truecrypt boot loader, but it did work.

To execute, get to the Windows recovery environment using Startup Repair or a Win 7 cd, mount truecrypt using UBCD4Win (or perhaps from a flash drive may be easier) and run that command above on the letter drive you've selected to mount on.

Props to OP:

If anyone has a way to re-encrypt a system (decoy) partition (1) in a hidden OS configuration I'd love your opinion. Right now it seems like it will prevent my ability to boot to one of the OS's.

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