As family truly does take things for granted and the "future problems is your fault" has happened to me on many occasions, mostly because the computer I was working on was very old in the first place. This is just one more reason why it is important to be doing the diagnosis BEFORE you start the work. That way you can let them know ahead of time, that because they are still running on Windows XP for example, they are doomed if you continue to use it.
With the cost of a new computer starting at just under $400 it usually doesn't make much sense to perform any major repairs if you aren't already using Windows 7 or 8 and if the repair requires hardware such a new hard drive, for example, due to the fact that you are looking at spending 1/4 of the price of a brand new computer just to repair an old one. A part replacement such as a power supply is no problem, since this has not affected the actual workings of the computer, once you have restored power to the unit but other then that..
