The installer (both classic and live) is correctly identifying that I have two Windows partitions, one NTFS, one FAT32. It suggests a mountpoint of /media/win_c for the first (NTFS) partition, but a mountpoint of /media/win_ for the second.

This is happening because in partition_table::assign_device_numbers, the call to isnormal_Fat_or_NTFS($_) for the second partition returns false because {fstype} is set to 'fat32', but in fs::mount_point::suggest_mount_points_always the call to isnormal_Fat_or_NTFS($_) returns true because {fstype} is set to 'vfat'.

This could be fixed by changing isnormal_Fat_or_NTFS() to also recognise 'fat32', but I don't think this is the right thing to do, as 'fat32' is not used anywhere else in fs::types.pm. I've not yet tracked down what is setting the fstype to 'fat32'.

This behaviour is also mentioned in bug #15636, but as that bug is mostly concerned with other issues, I've started a new one.

For reference, fdisk -l for my disk gives

Device         Start       End   Sectors  Size Type
/dev/sda1       2048    616447    614400  300M Windows recovery environment
/dev/sda2     616448    821247    204800  100M EFI System
/dev/sda3     821248   1083391    262144  128M Microsoft reserved
/dev/sda4    1083392 202409983 201326592   96G Microsoft basic data
/dev/sda5  202409984 210798591   8388608    4G Microsoft basic data
/dev/sda6  210798592 244353023  33554432   16G Microsoft basic data
/dev/sda7  244353024 277907455  33554432   16G Microsoft basic data
/dev/sda8  277907456 286296063   8388608    4G Linux filesystem
/dev/sda9  286296064 294684671   8388608    4G Microsoft basic data
/dev/sda10 294684672 328239103  33554432   16G Microsoft basic data
/dev/sda11 328239104 462542847 134303744   64G Microsoft basic data
/dev/sda12 462542848 479320063  16777216    8G Microsoft basic data

sda4 and sda5 are the two Windows partitions.