Get file manager to show ALL partitions

I am new to Debian.

How do I get the file manager to show all partitions ?

It is not showing a partition that has another distro on it.

I could not find Seamonkey in the package manager.

Is it not available for install ?

And the scanner program is using my webcam instead of the Canon MG 2220 scanner ??

Which desktop envirnment/WM and File Manager do you have? I know that most of them display all the partitions, The XFE on my system doesn't so i included them in my /etc/fstab as below: You could try that.

# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda3 during installation
UUID=c4a4f008-5d25-4959-b9a9-e9dbb85e6cad /               ext4    errors=remount-ro 0       1
# /dev/sda2
UUID=551e6e05-7b99-49fc-b804-2257fd63bae7 /data		  ext4 rw,errors=remount-ro 0	    2
# /dev/sda7
UUID=a6f2a270-a944-48bf-b741-ed6c2c6c7488 /data1	  ext4 rw,errors=remount-ro 0       2
# /boot/efi was on /dev/sda1 during installation
UUID=DC35-C34D  /boot/efi       vfat    umask=0077      0       1
# /home was on /dev/sda6 during installation
UUID=f40375bc-4844-46eb-b9d9-bc591767b3ab /home           ext4    defaults        0       2
# swap was on /dev/sda5 during installation
UUID=88981529-4b09-444a-9ad8-6c9bcae12789 none            swap    sw              0       0
/dev/sr0        /media/cdrom0   udf,iso9660 user,noauto     0       0

1) Run "sudo blkid". This will give you the UUID of all your partitions.
2) Create folders in your root(/) directory for every partition you wish to see in your file manager. If you look at my /etc/fstab above you will see that i've added /dev/sda2 which is my LMDE partition which will be visible in the "data" folder i created before and /dev/sda7 which is another partition i've set aside for storage which will be visible in the "data1" folder.
3) Edit your /etc/fstab file as above and substitute the UUIDs for the partitions you wish to see. (I am assuming they are ext4, if not put in the type instead of ext4 as above.
Reboot and all should be well.

Thanks, I think I have XFE.

Disk Manager, will work if it's installed.

What is the file system and type of the unseen partition?
It may need module for LVM, RAID, or extraordinary file system.
You may know by executing the following with root privilege

blkid
parted -l
fdisk -l

To get root privilege, simply

su -

and enter root password, or

sudo su -

and enter non-root (ordinary user) password, if your ordinary user is in sudoers group.

I got my problem resolved with my scanner in Slacko, so I deleted Debian.