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I got an issue with bitlocker on a win 8.1 Asus T100TA tablet. I got the bitlocker recovery screen by every startup, so I tried to find a solution. According to this article you have to pause, reboot and resume the encryption and everything will work fine after that. My Windows does not have a GUI option for that, so I had to do it from command line. The pause looks like this: manage-bde -protectors -disable C: and the resume looks like this: manage-bde -protectors -enable C:. By the resume I got an error message something like "no compatible TPM device found on the computer". I guess that is some kind of security related hardware which the tablet does not have. The bitlocker configuration tool version is 6.3.9600, do I need a more recent version?

According to a forum on GUI it is possible to resume encryption without a TPM device by using a "without TPM" checkbox. I used manage-bde -protectors -enable -help to find something about this in the manual, but there is nothing similar there.

I used manage-bde -status to get more info. According to it the key protectors are "TPM" and "numerical password" on the drive and it is AES-128 encrypted.

Any idea about how to resume bitlocker encryption from command line?

note:

Other strange phenomenons that when the screen goes black after inactivity I cannot turn it on again by shortly pressing the button on the tablet. When I press longer it resets the system. By shutdown something similar happens. It spins down the attached HDD and it appears to be turned off, but I have to press the button 2 times to start the system, because at the first time it appears to turn off the computer. Strange. So the system or some kind of driver appears to be unstable. I already run system integrity tests, but according to them the system is ok. It has an eMMC drive, and hdsentinel cannot recignoze it, so I don't have SMART info. Maybe the drive is dying in it, I don't know.

update

I checked in the device manager whether the tablet has a TPM. The found that there is a problem with the "Intel(R) Trusted Execution Engine interface", so it is some kind of driver or maybe hardware error, and there is a good chance it has this TPM, it just does not work well. It writes "status device power failure".

I checked the system logs. The "DptfPolicyLpmServiceHelper" caused some errors. According to a site it is some temperature sensor related stuff. The ms update just installed the driver for the sensor, so apparently they still did not manage to do it properly. Another more interesting error that the Trusted Execution Engine failed to perform handshake with the firmware. There are a few warnings too.

According to the system, it will re-enable encryption automatically after a few reboots, so let's see what happens.

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I think I understand the problem. This TPM device stores the bitlocker key to decrypt the drive. The Trusted Execution Engine (TXE) is the driver for this TPM device. According to the logs there is a power failure by the TPM, that's why the bitlocker cannot get the key from it and so I have to give the numerical password manually by every startup.

I reinstalled the TXE from the Asus site, but it did not help. Just to be certain I'll check the UEFI/BIOS, maybe the TPM went disabled somehow, but I think that is unlikely. Since this came suddenly and I did not change any settings or updated anything before it, I think this is a hardware failure and I have to replace the motherboard. So I contacted the local Asus service, but I think I'll end up buying an used motherboard and doing the job myself. Other options are disabling the TXE and using a shorter alphanumeric password instead of 40+ digits or disabling bitlocker entirely.

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