Wow all I asked is how long a mac will last not why I should get a pc instead..-___-
There are no guarantees. It could last 10 years or two months. On average a Mac is in service longer than a PC, but costs more. If I say you could expect a good 4 years of service from a Macbook Pro and it fails or becomes obsolete or orphaned after 2, does that provide you any comfort or recourse?
Your premise for asking was the necessity of having a working computer for a four year time frame on a budget of $3,000+. It would naturally imply that you are open to more economical alternatives.
Now I have a few questions for you.
If you have already decided that the Macbook Pro is the way to go, then why ask the question unless you are trying to justify the expense, either to yourself or to someone else who will funding the purchase?
Why have you limited your needs to only Apple products? There are plenty of legitimate reasons to do so, I am just interested in yours.
Why is it necessary to have a single machine for the duration of your education?
What are your current needs and projected (three years from now) needs for this computer?
What is the airspeed of an unladen swallow?