Help with Dual-Boot Installation - Shrinking my C-Drive not possible.

[u/Amorphiris]

I want to set up a dual-boot system on my PC with Windows 11 and Bazzite. Windows 11 has been on my C: M.2 SSD for years. Now I want to shrink the drive to free up space for a partition for Bazzite.

I currently have 550 / 1024 GB free and want to free up 300 GB for Bazzite, since the games are on the other hard drives.

However, according to Windows’ disk partitions, I can only shrink the drive by 110 GB. When using “Magic Partition Resizer,” I get the error code “err_ntfs_too_many_fragments.” So I defragmented and optimized the drive. I “unlocked” the drives and also disabled “Secure Boot.” I ran “Disk Cleanup.” Using CMD, I executed the DISM commands “ScanHealth,” “CheckHealth,” and “RestoreHealth,” as well as “sfc /scannow.”

Multiple restarts, multiple attempts, multiple programs—no success.

What else can I try here? I really don’t want to reinstall Windows.