it's been a few times now that my system completely freezes up (Ubuntu 16.04) where my mouse and touch pad seizes to work. The keyboard also doesn't respond. All that helps is to power down and restart via the power button.
Note: may it be that low RAM is the root cause? I have an Asus with 2GB RAM and 500GB HDD (Just asking)
Yes, your low RAM is probably the root cause. You must have configured a swap area and your system is using your disk as extra-RAM. But a disk is 1000x slower than regular RAM and the system slows down to the point of being unresponsive.
One solution is to identify the culprit (the process that eats most of your RAM) with top and see if it is dysfonctionning in some way. Else, if this program is not essential for you, you may want to uninstall it. If this is not an option, you can start it only when you need it, and stop it when you're done with it.
Another option is to let the OOM killer (*) do its job by reducing your amount of swap. You may have 1 or 2 GB of swap. The OOM killer will start to act when your swap is full (apparently too late for you) => reduce the swap partition to 100 or 200 MB.
(*) Out-of-memory killer, a kernel process that kills the processes that are too memory hungry.
