Ubuntu keeps freezing on me.

[Howlin1]

Hello, I am new to Ubuntu. I had it installed on an 8gb Medion USB key and for some reason Ubuntu keeps freezing every few minutes. The application that I would be using would freeze for a few seconds.
Would anyone happen to know why this is happening to me?

[nujinini]

Hello and welcome Howlin1!

How big is your RAM may I ask?

Can you please post the output of

$ free

[Howlin1]

Hello and welcome Howlin1!

How big is your RAM may I ask?

Can you please post the output of

$ free

On my laptop I have 2gb of RAM and on a desktop I tried it on (and the same problem happened) I had 3gb of RAM.
But

             total       used       free     shared    buffers     cached
Mem:       2051640     583488    1468152          0      38496     334528
-/+ buffers/cache:     210464    1841176
Swap:      1678332          0    1678332

[coopstah13]

its probably just an artifact of running it from usb flash, which isn't as fast as a hard disk, so any time something has to be loaded into memory from the flash drive it might freeze for a couple seconds

it could be graphics issue if you need a proprietary driver for your graphics card

[Howlin1]

Other than getting an external HD or doing installing Ubuntu onto my laptop is there anything I can do to stop this?
Also how can I get more space? Attached below is screenshot of my GParted. There are some partitions that have a lot of space and others that don't have much. The partitions that I seem to be using is sdb2 and / mount point (it's also booted from it).