This looks like a 3 year old laptop so this should be about the 10th or so pass with the canned air cleaning. It could be in need of repair but let's hear if you are doing your own maintenance.
My laptop e725 on windows 7 32 bit stops working suddenly when I am using it, particularly when I am connected to internet. It does not shut down though and I do not lose my work. It just stops working and when I press the sleep button it goes to sleep, on waking it up I get the log in screen and all my work/windows are as they were. I changed my OS twice and formatted C drive but it did not resolve the issue.