References
Official guide on Ubuntu Desktop
An easy and rich guide to the basics of Ubuntu Desktop:https://help.ubuntu.com/14.04/ubuntu-help/index.html
Workaround for frequent error reporting popups
In a terminal,
$ sudo rm /var/crash/*
(Reference:Online forum post)
More on virtual machines
How to create a VirtualBox VM from scratch:
You may refer to the guide from VirtualBox:https://www.virtualbox.org/manual/ch01.html#gui-createvm
Alternative(s) to VirtualBox
There are other alternatives for hosting VMs on your own computer, e.g.VMware. TheVMware workstation playeris free for download, however, it only runs on Windows and Linux.
Running 64-bit virtual machines
If you want to create your own VM and install a 64-bit OS, you will need to enable the feature in the BIOS, namely VT-x for Intel processors, or AMD-v for AMD processors