Vista - BitLocker Drive Preparation Tool Error

Hi,
Vista Ultimate (32 bit). Single partition 'C' drive.

I am trying to install BitLocker. I run the BitLocker Drive Preparation Tool and receive the following error:

A problem occurred while preparing the drive for BitLocker Drive Encryption.
Error: 0x80070005
Access is denied.

My basic understanding is that the tool should create an active partition S: of size 1.5GB and move the boot files to the new active drive S:.

Dell D820 with 30.2 GB free. Bios A09. TPM 1.2 chip is on and activated.

I tried running as Administrator. I tried searching MS Knowledgebase. I tried turning UAC off.

It seems like this should be easy.

Help?

Can you manually create that partition? If not that may be the problem....

Okay... no, I cannot manually create the partition. I don't understand why not. I am an administrator and the only user. There is plenty of free space. The drive is defragmented regularly... hmm... are there unmovable files up there at the end of the drive?

What to do?? Reinstall?

I cannot shrink the drive using Vista's Disk Manager - Access denied.

I cannot shrink the drive using Gnome Partition Editor - no error, doesn't clock, just simply refuses the command. You would think that with a third party partitioning tool that boots to a Linux GUI that it would work. The fact that it didn't work tells me that the problem isn't Vista per se; but, what does it tell me the problem is?

I tried deactivating and turning TPM off. I checked every security setting in the BIOS, nothing of interest.

Maybe I will try Acronis' Disk Director... maybe I will put the Vista CD's in, format the drive, and do a clean install, try the Drive Preparation Tool again.

I have no theories as to what the problem is and therefore no understanding of what to try next?

[... chirp, chirp... ]

Honestly, not sure, unless you already shrank the partition once- then you cannot shrink it again, AFAICT.

It seems like shadow copies were the problem. Turning off shadow copies appears to have solved the trouble.

I would have expected shadow copies to be movable files. I really don't know what happened, but turning shadow copies off and deleting old versions seems to have restored my ability to shrink the drive.

I hate that I can't tell what really happened.

Acronis' Disk Director wasn't any help either.

After stopping shadow copies though, Vista Disk Manager then allowed me to shrink the volume. Subsequently, the drive preparation tool also worked.

It appears that Gnome and Acronis would now work as well.

I can't think whether this would help someone in the future because I still don't believe shadow copies should cause the problem. It has to be a case of something, some file in a bad place for continuing with the shrink.

Shadow copy utility could not have been running when I ran Gnome. But, something stopped it.