Computer noise is normal... somewhat. Then there is the dreaded silence of death...
You see, there are several moving parts inside of your desktop computer. These parts are going to make noise, so that part is normal. Your computer has at least two fans, one on the CPU (central processing unit, or the brain of the computer) and the other on the power supply unit. An option third fan is sometimes located in the middle of the back of the case, directing airflow directly onto the CPU area, or venting the case itself. All of these fans will make noise.
In addition, your hard drive is comprised of small platters with magnetic read/write heads located in between the platters; a sort of sandwich if you will. Under normal operation, the hard drive is relatively silent, but as it gets older and it's mechanisms get more worn, it will generate some sound when accessing the drive. This is a good indication that you need to start shopping for another hard drive... and don't forget to regularly back-up the contents of the drive while you're at it!
Two more things that generate noise on your computer are your CD-ROM (and DVD-ROM) drives and your floppy drive (if you still have one!). These devices spin your media at phenomenal rotation rates, and generate heat as well as noise. However, these devices have a noise that you should become fairly familiar with. Any noise that appears abnormal from these devices probably indicates a problem with the device. For example, a grinding noise in the floppy drive may indicate a bad floppy disk, or a bad drive. CD-ROM is the same way ... a drive that has to be repeatedly opened and closed before it will access a CD could indicate a problem with the CD or the drive. In both cases, a careful examination of the media will help eliminate the media and point to the drive itself as the source of the problem. A good question to ask when encountering this type of issue is if the disk will work in another computer. If so, the problem is most likely your drive.
However, none of the things discussed so far describe the two most ominous sounds that can come from your computer: the whining grind of bearings going out, and complete silence. For the first issue, when the bearings in any of your fans start to go out, it starts to whine and grind. It will sound exactly like any other fan bearings that you might have heard go out... from an air conditioner unit to a box fan... the fan bearings all sound the same when they start to fail. At first this noise will be intermitten... but after a while it will become severe and nonstop. At this point it is imperative that you purchase a fan to replace the one that is going out. Why? Because what comes next can be very destructive...
Complete silence. No fan sounds. No grinding. Worst case scenario: it's the CPU fan gone bad, and every second you use your computer you are burning up the CPU chip. Most computers today are designed to turn themselves off once the temperature on the CPU reaches a certain level... before damage takes place. However, this safety feature doesn't always prevent damage from occurring. After you get the fan fixed, you can experience random shut-downs and system errors that are directly related to a previous overheating incident. So, it is best not to run your computer at all during times when overheating may be an issue.
So the bottom line? Get to know your computer! Some noise is normal... but excessive noise from any component on the computer usually indicates excessive wear and tear, not to mention possible emminent failure. So be alert and aware of what your computer sounds like now,... before it has any problems.
About the Author: Michael Arcand is a CompTIA A+ Certified computer technician and entrepreneur specializing in computer tips and tricks for home users. His latest venture is online at http://www.techsupporthelpdesk.com, providing cost-effective tech support for home and small business users.