3 strange things have been happening to my computer

1: it froze the second i looked at the smiley picture and it isn't any viruses or the fact that its old but it doesn't happen anymore

2: it scrolled by itself and i wasn't laying on the keyboard or touching the mouse

3: when i was restarting it (due to updates) i have the smiley picture as my desktop picture and when he was restarting it froze when the smiley picture on my desktop came up and until i touched the power button it stayed with that picture on it