Compressing my drive killed my login to the Windows side

[Corkster52]

Yesterday morning I got the bright idea, since I had so many problems running out of space, to compress the drive and the underlying folders. The process said it would take about 6 hours but was complete in under an hour. Anxious to reboot and see just how much more room I had, I did so very quickly and found that my login on the Windows side (Bootcamp) failed several times and found no way to fix it. I did see one site that mentioned doing an alteration of the registry but I can't find a way to access it. Because I can't get into Bootcamp, I can't find a way to see which version is installed. Attached is the error I repeatedly encountered. Thank you in advance for any feedback you can provide!

 

[MacInWin]

Welcome to the forum.

So many questions--what Mac, what version macOS, what do you mean by "compress the drive." Nothing was attached that I could see, so what was the error message?

You DO have backups of both the Mac and Windows systems, right?

 

[Corkster52]

Welcome to the forum.

So many questions--what Mac, what version macOS, what do you mean by "compress the drive." Nothing was attached that I could see, so what was the error message?

You DO have backups of both the Mac and Windows systems, right?

Sorry about not putting enough info in. Here's what I have:
Laptop MacBook Pro16,2 (20G314)
Apple T2 Security Chip
19P647 Firmware
Apple SSD AP1024N
Bootcamp 60.24 Gig NTFS
macOS 11.6.2

On the compression, I just hit properties for the C drive and said to compress it along with its subfolders.

The error says: "The User Profile Service failed the sign-in. User profile cannot be loaded."

I don't think we (this is my wife's laptop) have done a backup. She has had it for for a year.

 

[vansmith]

Can you please tell us what you did to “compress the drive” as per @MacInWin’s post? This will be a key first step for us.

 

[Corkster52]

Through Windows Explorer, I opened up properties, and checked the compress box at the bottom...
Like this....

https://imgur.com/NmHeJO7

 

[chscag]

I believe you locked yourself out of Windows. The T2 security chip recognizes Windows as a legal installation which is why the initial Boot Camp setup works and Windows can start up.

When you compressed Drive "C", it probably changed its look so that now the EFI startup no longer works and the T2 security chip no longer recognizes Windows.

You're probably going to have to redo Boot Camp and reinstall Windows. I have no idea how that can be done since you're running Big Sur. You may have to remove the Windows Boot Camp partition and somehow reallocate that space.

 

[Corkster52]

I believe you locked yourself out of Windows. The T2 security chip recognizes Windows as a legal installation which is why the initial Boot Camp setup works and Windows can start up.

When you compressed Drive "C", it probably changed its look so that now the EFI startup no longer works and the T2 security chip no longer recognizes Windows.

You're probably going to have to redo Boot Camp and reinstall Windows. I have no idea how that can be done since you're running Big Sur. You may have to remove the Windows Boot Camp partition and somehow reallocate that space.

Ouch! Thanks for your response, as disheartening as it is.

I have been online with both Apple and Microsoft and each of them says it's the others' problem.

For the little I have seen so far, removing the partition looks relatively straightforward but I really can't afford to lose the data. I did a backup on the Mac side yesterday, that took about 152 GB, but there was a BOOTCAMP exclusion there that I could not disable. Any thoughts on how best to grab everything I can before taking the giant leap to remove the partition?

 

[pjhutch]

I would get hold of a Linux Live CD, then you can boot off your DVD drive and you can mount the Windows partitions on the Mac and you can copy off the data to an external drive.
See KNOPPIX Linux Live CD or Home - Linux Mint