If you are using Linux Mint Gnome or Linux Mint Debian Edition, you will notice that Ctrl+G or Mark All Upgrades is disabled. This has been done to prevent users from installing upgrades that have not been tested and verified to work by Linux Mint team. Read more in this discussion.
There are many Virtualization solutions that run on Linux and of course Linux Mint. Oracle Virtualbox is a virtualization software available for Linux, Solaris, Windows and Mac, . It is available from the Linux Mint Julia Repositories and can be installed directly via Software Manager. However, if you install the open source version i.e. virtualbox-ose [...]