Warnings:
Make sure the hidden partition is NTFS!!!!
No responsibility taken if you follow these instructions and you fubar your disk. If in doubt, use a graphical tool like Partition Magic to help you out.
Open a cmd window
Type diskpart and enter
A seperate diskpart window kicks off with a DISKPART> prompt.
Find the partition you want to unhide using LIST and SELECT commands
DISKPART> list partition
Partition ### Type Size Offset
————- —————- ——- ——-
Partition 1 Primary 55 MB 32 KB
Partition 2 Primary 89 GB 55 MB
Partition 3 Primary 60 GB 89 GB
DISKPART> list disk
Disk ### Status Size Free Dyn Gpt
——– ————- ——- ——- — —
Disk 0 Online 149 GB 0 B
Disk 1 Online 5831 MB 0 B
DISKPART> select disk 0
Disk 0 is now the selected disk.
DISKPART> list partition
Partition ### Type Size Offset
————- —————- ——- ——-
Partition 1 Primary 55 MB 32 KB
Partition 2 Primary 89 GB 55 MB
Partition 3 Primary 60 GB 89 GB
DISKPART> select partition 2
Partition 2 is now the selected partition.
DISKPART> detail partition
Partition 2
Type : 17
Hidden: Yes
Active: No
Offset in Bytes: 57576960
There is no volume associated with this partition.
DISKPART> SET ID=07
DISKPART> detail partition
Partition 2
Type : 07
Hidden: No
Active: No
Offset in Bytes: 57576960
Volume ### Ltr Label Fs Type Size Status Info
———- — ———– —– ———- ——- ——— ——–
* Volume 3 F NTFS Partition 89 GB Healthy