I am a new Ubuntu user and I moved to Ubuntu 16.04 a week ago.
When I turn on my PC I can use it normally for about 5 minutes. After that, it is impossible for me to open any app, and the ones already open just don't respond, although I can still navigate on my PC.
When I go to the process manager, I can see all my apps that are not responding but I can't kill them.
Also when I click on shutdown button (or reboot), my PC freezes.