De acordo com a resposta do fórum do Microsoft TechNet:
In my experience these are two reasons to not showing this check box:
- NTFS compression is a function of the NTFS file system and as such is available only on volumes formatted with NTFS.
- The compression algorithms in NTFS support cluster sizes of up to 4 KB. When the cluster size is greater than 4 KB on an NTFS volume, none of the NTFS compression features are available.
Fonte: link
Verifique o tamanho do seu cluster NTFS para ver se esse é o motivo pelo qual, por sua imagem, a unidade já é NTFS.