What Is the System Reserved Partition and Can You Delete It?
Windows 10 and Windows 11 create a special “System Reserved” partition when you install them on a clean disk. Windows doesn’t normally assign a drive letter to these partitions, so you’ll only see them when you use Disk Management or a similar utility.
Hannah Stryker System Reserved Partition Boot Manager Boot Configuration Data Disk Management System Reserved
Source: howtogeek.com