While preparing a Linux Mint installation, I deleted a roughly 500 MB Windows recovery partition so I could reduce the disk to three partitions and create space for Mint on a fourth partition. The disk uses MBR, and I'm now running into EFI-related issues during installation. I restored the space to the C: partition, shrank it again, and tried creating a 1 GB recovery partition so I could convert the disk from MBR to GPT. However, the new partition is being created as logical instead of primary. There are currently only three visible partitions, so why is this happening, and how can I create a primary partition or safely convert the disk to GPT?
2 Answers
Be very careful here. Deleting or resizing a Windows recovery partition, changing the partition table, or converting MBR to GPT can make the system unbootable and can potentially affect the entire disk, not just files stored on C:. Back up all important data first. Also, shrinking by only about 1 GB can cause partition tools to create small additional structures for alignment or recovery purposes, so inspect the full disk map rather than relying only on the Windows drive-letter view. For a modern Linux installation, backing up the disk and converting it properly to GPT—then installing in UEFI mode—is generally safer than repeatedly rearranging MBR partitions.
A logical partition is created inside an extended partition. On an MBR disk, only four primary partition entries are available, and Windows Disk Management may create or preserve an extended partition when working around that limit. The fact that you see only three partitions does not necessarily mean there is no extended-partition structure. Check the complete layout with a partition manager before making more changes. If you need a fourth primary partition, you may have to remove or convert the existing extended partition, but that can require deleting partitions and should not be attempted without a verified backup.
Simply extending the logical partition back into C: and shrinking C: again will not reliably turn it into a primary partition. The partition type and the surrounding extended-partition layout must be changed explicitly with a suitable partitioning tool.