A Windows 10 upgrade may leave more than one small hidden partition, especially if an older recovery partition was too small for the new WinRE image. Most are not junk. Identify the active boot and recovery partitions before deciding whether an extra one can be removed.
Open Disk Management and note the physical disk, partition order, size, and labels. The EFI System Partition contains UEFI boot files; the Microsoft Reserved partition supports GPT management; the active Windows Recovery partition holds WinRE; an OEM partition may contain factory recovery tools. None should be deleted merely because it has no drive letter.
Run an elevated reagentc /info and record the Windows RE location. Match its harddisk and partition numbers to the current disk map, allowing for numbering differences in tools. If the location is unclear or WinRE is disabled, stop and resolve that uncertainty before touching any recovery partition.
Step 1. Copy personal files to another physical drive, then create a whole-disk image including all small system partitions. Confirm bootable recovery media can see the image.
Step 2. Record the current ESP and active WinRE location, plus any OEM recovery function you may want to keep. If the PC supports factory restore, test or document its availability before removing an OEM partition.
Step 3. Identify one candidate that is clearly an old, unused recovery partition. If two partitions look similar and you cannot prove which one is inactive, do not delete either.
Deletion permanently removes that partition's contents and creates unallocated space. It does not automatically extend C:, especially when another partition lies between C: and the newly freed area.
Step 1. In Qiling Disk Master's Disk management view, select the exact old recovery partition by disk number, position, and size. Recheck that it is not the ESP, MSR, active WinRE location, or OEM partition you need.
Step 2. Choose Delete for the selected partition. Read the data-loss warning and confirm only after matching the target to the written record. Unlike some resize workflows, deletion may not offer a separate preview; do not assume one will appear.
Step 3. Wait for completion, then restart Windows. Run reagentc /info again, confirm Windows still boots and WinRE is enabled, and inspect the new unallocated area in Disk Management. If recovery fails, use the verified image to restore the prior layout.
If the unallocated space is not adjacent to the partition you want to grow, do not convert the disk to dynamic as a shortcut. A separate move/resize plan may be required and can be riskier than leaving a small unused area alone. For a few hundred megabytes, the safest choice may be to keep the spare space rather than disturb a working boot layout.
Classify every hidden partition, verify the active WinRE location, and remove only a proven redundant partition after a tested whole-disk backup.