This however does not mean that your power supply is in fault. A 'computer hang' could be the result of a buggy operating system, drivers, or even faulty hardware!
The problem with these hangs is that they are often very difficult to track down since there are a number of possible causes. The best thing you can do is to follow a few basic steps to ensure the computer is healthy.
If you feel comfortable, open your case and check all fans on your system, including the CPU and Video graphics fan (if any). In my experience I have found that most video card fans are likely to fail and any 'no-brand' CPU fans. Depending on your motherboard, you might also take a look at the motherboard in case there is a fan on the chipset.
Coming to the operating system, a general cleanup is recommended. Dive into the Add/Remove programs under control panel (assuming your running Windows) and remove any unwanted applications. You can also download a registry cleaner and run it to ensure your Windows registry is nice and clean.
Lastly, you can try the latest service pack for your operating system to ensure critical files are updated. Also check your antivirus definitions are up-to date. If you haven't got an antivirus, you should download and install one given the number of viruses in the loose these days!
If after all the above your problems continue, then you might want to send the computer to a local computer store for a health checkup.
Hope the above helps solve your computer problems!
This was first published in February 2004