One more bit of code to check the UUID on /dev/sda8 OP.
If that gives an output, I'd recommend edit /etc/fstab (gksu gedit /etc/fstab) and use uuid= in fstab like has been done for the root partition but for swap, removing the /dev/sda8 (see edit below sda7 is the wrong partition for fstab and swap in your case) bit. UUIDs are a far more flexible means of mounting.
sudo tune2fs -l /dev/sda8 | grep UUID
Once the uuid is added to the /etc/fstab file use,
the swap partition will now be mounted.
To use as swap,
If you can't find the UUID on /dev/sda8, ie no output above you will need to set one
sudo swapon /dev/sda8
This will actually set a new UUID to the partition. Find what it is for use in /etc/fstab from the first tune2fs command above.
sudo tune2fs -U random /dev/sda8
@ Bashing-om, /dev/sda8 shows as linux swap / solaris in that attachement not windows, check again please. Cheers.
Edit: your /etc/fstab points to /dev/sda7 the swap partition is /dev/sda8, first retry editting /etc/fstab to sda8 . Might be an easy fix, but UUIDs would be better imo. cheers