Invalid Partition Table after connecting USB drive

Question

I have a Latitude E6420 notbook (about a year old), running Win7/64. As it is a business computer containing some sensitive data, the hard drive is encrypted, and I usually access it with the fingerprint sensor.

A few days ago I needed to change something on a hard drive from another computer. I plugged it into a HD enclosure to access that HD through the laptop. Upon connecting the Hard drive, the laptop froze. I disconnected the USB hard disk, and rebootet the laptop. When booting, the fingerprint dialog comes up, and immediately after swiping my finger the following line shows up "invalid partition table", and all I can do is to turn off the laptop again.

I have checked out a few things with the "Testdisk" software, but it tells me that it can't find ANY partition information on the hard disk.

Since the computer shows the fingerprint dialog, there must be something on the disk (unless this is stored somewhere else? BIOS?). If that is the case, I think that something probably scrambled my (encrypted?) partition table. How do I fix this? Is there a tool to fix this encrypted partition table? Or am I on the wrong tree here, and this has nothing to do with the encryption?

Is there perhaps a tool to decrypt the HD and THEN try to fix the problem?

Thanks.

osprey4 · Answer

Hi Mike_bo, Since it's a business machine, I assume you have IT support and suggest you let them have at it. I honestly wouldn't touch it.

mike_bo · Answer

Yeah. The business is me.... No other IT support.

osprey4 · Answer

Sorry to hear about that. I assume you've got everything backed up so an OS restore would likely be the fastest path forward.

mike_bo · Answer

Unfortunately I just got back from 3 weeks of traveling and this happened before I had the chance to backup everything (mostly because the server with the backup drive was having the problem that made me connect its drive to the laptop). So every piece of help is appreciated.

Is DELL monitoring these forums, or do I need to contact them separately?

mike_bo · Answer

Ok, so I just talked to DELL support, and their only solution was to get a new HD. That will not bring back my data. So I am willing to try a few things. But perhaps someone can answer a question for me:

I encrypted my drive, and I am now not certain how that actually works. When I boot up, the first thing I see is the "DELL Preboot manager" which asks me to either swipe my finger or enter a password. After that, it used to boot into Windows and then show me my desktop (no separate login required). Now, of course, I only get the "invalid partition table" line.

Dell says that using their encryption, the entire HD is encrypted.

Now, if I interpret that correctly, the preboot manager is a piece of software that sits somewhere in the BIOS, and once I have signed on correctly, it intercepts all HD commands and encrypts/decrypts them. So, if there is a command to read something from the HD, it intercepts it, finds it on the hard disk, decrypts it, and hands it back to the requesting program. Now, my question is: Does the partition table get also scrambled? If so, would a piece of software running from a bootable CD be able to actually fix this, or would is scramble it even more?

I just booted from the resource disk and selected "repair installation", then selected "startup repair". The laptop has been sitting now for over an hour spinning it's wheels and saying "Attempting repair..." I am wondering if this software would even be able to repair an encrypted HD. I did have to swipe my finger before it would boot, so I am (slightly) hopeful...

osprey4 · Answer

Because of the encryption, you're pretty much stuck working with Dell. I can't help with that.

Hope you don't lose too many files. I understand when you're on the road it's a pain to maintain backups. You might want to think about a cloud data backup service.

Storage, Drives & Media

Invalid Partition Table after connecting USB drive

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