Resetting the TPM module on my motherboard?

Question

I've got a TPM set up on a motherboard, but the motherboard has now been swapped, and the HDD is still the same.

Would like to basically reset everything to factory defaults, but the HDD is encrypted and I can't seem to reset the TPM.

No matter what I always end up on: "Please enter passphrase for disk KINGSTON:"

What I've looked at:

The BIOS setting has:

-> Advanced -> Trusted Computing -> Pending Operation -> TPM Clear

Which I've tried, but hasn't been successful.

There's also a pin on the motherboard for "Security Override Jumper".

I've tried swapping it which has set it to ME Recovery Mode, and then tried to TPM Clear option, but that hasn't done anything either.

I think I may be missing something obvious. I want to both reset the TPM encryption on the HDD and immediately run a new install script...

I would think that resetting the TPM would also kind of force the HDD to be cleared of all data.

Any ideas?

score 1 · Answer 1 · answered Oct 08 '20 at 06:22

Clearing the TPM doesn't wipe the disk, it just makes it unreadable because the disk encryption key is lost. Depending on whether the disk itself was encrypted or its partitions were encrypted, you might be able to wipe it.

I know Dell's disks cannot be wiped (without passphrase) if they were encrypted at the disk level; your might be too.

score 0 · Answer 2 · answered Oct 08 '20 at 15:22

0

If you cleared the TPM while it still had the hard drive password in it, then it is lost forever.

A vendor-specific tool might be able to wipe the drive (and its password along with it) but this isn't very common. Most likely you will have to bin the drive.

answered Oct 08 '20 at 15:22

Michael Hampton

237,123
42
477
940

So what exactly does running "TPM Clear" actually do? – Rail24 Oct 08 '20 at 17:52
@Rail24 It permanently erases all the secrets held by the TPM chip. – Michael Hampton Oct 08 '20 at 18:20

Resetting the TPM module on my motherboard?

2 Answers2