Linux Mint 17.3 doesn't recognize Windows 10

Hey guys!

I'm was going to install Linux Mint 17.3 parallel to Windows 10, but the Installer don't show the option for installing parallel.
I already googled about it, but i can see all partitions, and no errors are there when i type "sudo parted -l" in the terminal (Live-Version).

mint@mint ~ $ sudo parted -l
Model: ATA SanDisk SD7SB3Q2 (scsi)
Disk /dev/sda: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 1049kB 525MB 524MB primary ntfs boot
2 525MB 256GB 256GB primary ntfs

Model: ATA HGST HTS721010A9 (scsi)
Disk /dev/sdb: 1000GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt

Number Start End Size File system Name Flags
1 1049kB 1000GB 1000GB ntfs Basic data partition msftdata

Model: Generic Flash Disk (scsi) /* This is just my USB Stick on which Linux is "installed" */
Disk /dev/sdc: 8189MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 16.4kB 8189MB 8189MB primary fat32 boot

This is what happens if i type "sudo parted -l" in terminal. I don't want to partition manually, but if it doesn't work anyhow else, i
would do it with a tutorial or something.

PS: I need Windows for school, because they're using just windows, and i need the office programs...
And i'm german, so sorry for my bad english.

Hope that you can help me!
Schneema