Troubleshooting is one of the most difficult subjects to master because so much of it depends on what, specifically, is happening to the computer. Since so much can go wrong with a computer, there is quite a bit that a successful troubleshooter needs to know.
In general, there are three main strategies that are effective. All three of these strategies begin with the same first step: define the problem. Without knowing what is actually going wrong, you have no hope of fixing it. Try to gather as much information about the problem as you can. Anything--from what programs are affected, to what you were doing when the problem started, to the error messages you get--could be the key to solving the problem.
Once you've discovered that something isn't working on your computer, the next step is to narrow down what the problem is affecting. Is it a single program that has issues, or the entire operating system? Does the computer even turn on? When did the problem start?
Often, a computer may start showing signs of a problem after new hardware or software is installed. If that's the case, you may want to make sure that the newest addition to your system isn't the culprit by removing it and checking for the error again. New components can cause problems even if they are not broken. Some software and hardware simply do not play well together. This is something you may want to look up (see Strategy 1 below).
Another thing to check is your cords. A loose cord could change the way your hardware is working without disabling it altogether. Make sure none of the plugs are loose, that all of the screws are tight, and that all of your components are turned on.
Once you've actually defined the problem, you can move on to the different methods of figuring out how to fix it.
Strategy 1: Research
Since there are only so many ways that a computer can break, it is likely that someone else has already experienced your problem. If you're lucky, they will have posted online a description of how they fixed the problem.
As soon as you've defined your problem, you can begin searching for someone else who has fixed it before. Search engines tend to be excellent resources for this. You may be able to find a step-by-step guide to your problem by searching for some key points that you came up with during the definition step. There are also many books about fixing various computer issues. Check online and retail bookstores (including used bookstores) and the library (try an online search of the library catalog before visiting the library)--that deal with fixing computers. You may even be able to find electronic versions of useful books.
If you don't manage to find a Web site that has the answer to your question, don't despair. There are many troubleshooting forums online where you can ask your question. Just be as precise as possible when you're asking about your problem. If there's one thing that people on these forums hate, it's not being given enough information about the problem they're supposed to help fix. And check the backlog of issues before posing your question.
STRATEGY 2: REBUILDING
You can try to rebuild your computer. This can take two forms. If you identified a hardware problem in step 1, then you would proceed by removing all unessential hardware from the computer and turning it on. If the error reoccurs, then you will have narrowed the broken component down to one (or more) of only a few things. If the error is missing, then you know that the current hardware works. After that, add in one component at a time, checking to be sure that the computer works each time. Eventually you'll install the component that is causing problems. Once identified, it can be replaced.
If you found that the error was with software in the first step, you would proceed by uninstalling software or reinstalling the operating system. If that does not fix it, the error may be with hardware. After reinstalling the operating system, reinstall your programs one at a time. After each program is installed, make sure your computer is working. You will eventually find the program that is broken.
This method is the most time consuming, but it can have a great chance of success. It may fail if the problem is caused by two or more components (software or hardware) fighting with each other over resources. If you think the problem may be with the interactions between components, as opposed to simply a broken component, try using the next method.
Strategy 3: Guess and Check
This can be the least effective form of troubleshooting, but it is also the most common. When using this form of troubleshooting, you make your best guess about what is causing the problem and then go about fixing that. For example, if your computer refused to turn on and you thought your power supply was broken, then you would replace the power supply and see if that fixed anything.
When this method works, it works quickly and well. If it doesn't work, you could end up wasting a lot of time or money on things that don't affect the problem at all.
This method works well for people who have a lot of experience using and troubleshooting computers. The more you know, the more accurate your guess will be. If you don't have a lot of experience troubleshooting, you will probably be better off choosing one of the other methods.