Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
When you say it shuts down 3-4 times a week, what do you mean by shut down? Do you mean that it completely cuts off like the power was cut off?
Or, does it freeze or lockup but you can still tell the machine is turned on?
Can you take a picture of that screen the next time you see it.
This may seem like a strange request, but I can tell a lot from the format and the way the message displays, as to what the issue is.