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PGP Recovery Disk Decryption Process

Created: 13 Oct 2012 • Updated: 28 Dec 2012 | 8 comments
This issue has been solved. See solution.

All,

I've got a laptop that managed to get a corrupted BCD, so Windows 7 would not start.  We know how it happened, and knew it should be simple to fix if we could simply run the Windows 7 startup repair.  Another system running PGP was not readily available, so I figured I'd just decrypt using the PGP recovery disk.  This was clearly a very bad idea.  

It's been "stuck" at 99% for over an hour.  Some other posts I've found seem to indicate this is not uncommon, so I'm not too worried about that.  However, I was not aware at just how incredibly long this will take.  The estimate I found was 5 days for a 700GB drive.  I don't have that kind of time, and will have access to another computer running PGP tomorrow.  

So my question:  Is it possible/safe to stop this process now that it has been started?  The documentation I've found seems to give some pretty stern warnings about not stopping the process once it has begun, but I really need access to this machine ASAP.  

Any help/advice would be greatly appreciated!  

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Tom Mc's picture

I wouldn't stop it before it completes.  That warning has always been there regarding the WDE Recovery CD decryption, and you are likely to lose your data on that disk if you do stop before completion.  It is very likely that decryption is still progressing properly, and your stated expectation about how long this will take to complete is correct.  I am aware of one or two people having reported that they stopped this decryption and where then able to later start it again and successfully complete decryption, so it appears there is some chance of not losing your data if you should decide to take that risk.

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aparker_SIA's picture

Thanks, that's what I was afraid of.  

Slightly different take on this question.  I'm not too concerned about ever getting the disk completely decrypted as long as I can access the data on the drive.  If I were to stop the decryption, would I at least be able to slave the drive to another computer running PGP and access the data?  

Appreciate your help!

Tom Mc's picture

I wish I knew of some study on this that would let me give you the odds of each such option, but I don't have any such data.  I would think that this chance of success would at best be the same chance as being able to subsequently successfully resume decryption.  If the data is important, I wouldn't take the chance.

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SOLUTION
tmcnulty1982's picture

I just got myself in the same situation.  How long did this end up taking?  Or how long would it be expected to take for a 300GB 7200 RPM drive?  It's pretty frustrating that one can download the recovery disk and innocently click 'D' to start the decryption process, without so much as a warning that it's going to take forever or that the process CAN'T be interrupted.  Good thing I decided to google around before powering off the machine.

Tom Mc's picture

The PGP Desktop User's Guide states:

Caution: Once you have started to decrypt a disk or partition using a recovery disc or diskette, do not stop the decryption process. Depending on the size of the disk being decrypted, this process can take a long time. A faster way to decrypt the drive is to use another system that has the same version of PGP Desktop installed on it. For more information, see Decrypting a PGP WDE-Encrypted Disk (on page 168).

The Knowledge Base Article  includes:

Warning: Use of the PGP Recovery Disks should be used as the last step when attempting recovery. Should there be a power loss while decrypting with the recovery disk, the result to the disk could be fatal and non-recoverable.

How long your WDE Recovery CD decryption will take depends on the hardware components of your machine.  Based on my experence, and your reported disk size and speed, I would give a very rough estimate of 4 days.

 

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aparker_SIA's picture

I'm completely with you, it's absurd.  The fact that there is not some sort of very stern warning indicating that the process has the potential to take WEEKS is ridiculous.  But I digress.  

Mine did complete successfully, but it took rigtht at 15 days on a 500GB 7200RPM drive.  This was on on a Dell Latitude E4310 with a 2.5 GHz i5 and 8GB RAM.  I did speak to a tech on the phone the following day, and he explained that the disc runs the decryption as a 16-bit process, which greatly reduces the potential processing power and memory resources available.  I'd imagine this plays a large part into why it take so long.  

Tom Mc's picture

I'm surprised it took a disk your size that long - several days longer than what I've seen.

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tmcnulty1982's picture

When I see the words "long time" in computer manuals, I think hours, not days.  In the past 3 hours my machine's gone through about 3%, which means roughly 4 days remaining, assuming the same decryption rate.  Ouch.

And again, the recovery disk should really make you confirm that you REALLY want to do that before starting the process.  What if you just hit D by accident?

Pretty ridiculous.