Guild Wars 2

My problem is that after logging on (3-20m after usually) my computer begins to lag, which gradually becomes worse until it shuts off unexpectidly. My guild says it is probably a memory leak (i got plenty of fans). Is this probably the issue, or are there other possible explenations?

http://en.wikipedia.org/wiki/Memory_leak it has nothing to do with fans =]

You should check your cpu/gpu temperatures. It might be overheating and slowing down performance.