Insufficient Storage Due to Hidden Partition Misconfiguration

This cause is confirmed when the disk shows multiple fragmented, small partitions (EFI, Recovery, MSR) surrounding the C: drive, preventing the extension of the main partition. Verify this in Disk Management by checking if the 'Extend Volume' option for your C: partition is greyed out despite having unallocated space elsewhere on the physical drive. This occurs when partitions were manually created or improperly sized during the initial installation.

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