I just installed official windows 11, my ssd spcae has 27gb less space after install, but when I select everything on my drive C and check properties, it shows only 12.8gb size on disk. I'm wondering where the rest of the space is as properties shows 27gb used.

 

that is a fresh reset install, not keeping any files

 

The disk space discrepency could be dow to a memory swap file that the OS installer has created.

 

Could be your hibernate file, check this, follow the steps and it will remove about the same space you're refering to...

https://www.howtogeek.com/howto/15140/what-is-hiberfil.sys-and-how-do-i-delete-it/

 

this freed just 2gb

 

If you install Windows and opt to keep existing programs and files, you'll find that the install creates a backup of the old windows installation in a directory named windows.old. You can delete this using 'Disk Cleanup' and selecting the system files option.

 

yhup did that

 

Did windows 11 create any additional partitions on your SSD?

 

I installed it but as a VM through Parallels Desktop. It's on a VM because Intel based macs doesn't support TPM chip so I don't really care what will happen with it and i'm using it as a test VM only. My first impression is that till now everything works (including updates)

 

27GB is pretty normal for a Windows 10/11 install. You may have some hidden stuff but besides that should be fine.

 

You can install without TPM. https://www.ghacks.net/2021/10/11/disable-tpm-secure-boot-and-ram-requirements-for-windows-11/

 

That's true but I read in couple of places that windows update won't work. Despite that, couple of people claimed that windows update DOES work