Comment 25 for bug 259540

I saw this error when trying to install Linux on my Windows 7 machine. Eventually I solved it.

My issue was that at some point the partition table had become corrupted - or mislabeled. The disk was labeled gpt but seemed to be actually using a standard mbr type layout. The tools fdisk, diskpart, gparted couldn't fix the problem for me.

I fixed it by booting into Linux Live USB, installing and using testdisk to analyse my hard drive and then re-write the partition table after confirming that it found all the partitions. Immediately after running this fix gparted could see the partitions on the disk.