So there are more than 2 disks and the Knoppix USB...
Inside your PCLinuxOS installation, give the following command as root:
fdisk -l
This will show us information of all the disks in your system...
This is the output of fdisk -l:
[root@localhost ~]# fdisk -l
Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xad59c312
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 206847 102400 7 HPFS/NTFS
/dev/sda2 206848 1953521663 976657408 7 HPFS/NTFS
Disk /dev/sdb: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x360a360a
Device Boot Start End Blocks Id System
/dev/sdb1 * 63 608349419 304174678+ 83 Linux
/dev/sdb2 608349420 625137344 8393962+ 5 Extended
/dev/sdb5 608349483 625137344 8393931 82 Linux swap / Solaris
Disk /dev/sdc: 4037 MB, 4037017600 bytes
100 heads, 36 sectors/track, 2190 cylinders, total 7884800 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdc1 * 8064 7884799 3938368 c W95 FAT32 (LBA)
Disk /dev/sdd: 8086 MB, 8086618112 bytes
255 heads, 63 sectors/track, 983 cylinders, total 15794176 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x04dd5721
Device Boot Start End Blocks Id System
/dev/sdd1 * 63 15794175 7897056+ c W95 FAT32 (LBA)
[root@localhost ~]#