Life of PC or Laptop mostly depends upon the way it is used. If used properly then it will run smoothly for long time and if not used properly then it will have short life. Here are some tips regarding computer maintainance.
Always keep liquid or food iems away from PC as if by mistake it fells then it can damage PC.
Always install antivirus in your PC with latest version.
Always handle it with care.
Always carefully insert and remove external devices.
So you must follow above tips and keep your PC at good condition