A horse.
Chocolate Ice Cream in July!
Because they don't have a leg to stand on. Note: I'm a right leg amputee and I made this up myself.
None. Horses are not known to use operating systems nor computers for that matter.
A horse walks into a bar. Bartender: why the long face ? Horse: because I'm a raging alcoholic.
She was looking at a bear and thought it was a sofa due to the four legs.
His hand caught fire.