One major source of problems with the Mac OS comes from Extension conflicts. This happens when two or more extensions don't like each other, and start to brawl. You will have to take on the roll as referee, and stop that fight. But, to make sure it's an extension conflict, First you must start up with extensions off, or with a minimal extension set.
   To start with extensions off, hold down the shift key during startup. Many of the features you know and love will be gone, but that's OK. If you need certain extensions to run the program you are having troubles with, open up the Extensions Manager in the Control Panels folder, create a new set, and un-check all but those extensions.
   If you come to the conclusion that it is an extension conflict, you will have to take that newly created extension set (or make a new one), and start turning on extensions a few at a time. (Tip: You cn hold down the spacebar at startup to open the Extensions Manager before all the extensions load, saving you a restart). If the problem happens after those extensions are enabled, you know it's one of those extensions. This can be a very long and tedious process. That's where a program called Conflict Catcher can come in handy. It will automatically enable and disable extensions, relieving you from a lot of work. I highly recommend it.

Desktop files are what hold information such as custom icons, get info comments, and more. If these files get corrupted, you can have serious problems. Ranging from generic icons, to aliases not working, to programs developing problems, it's never good to have a corrupt desktop file. Fortunately, it's quite easy to remedy this problem. Just pick up a copy of TechTool, and and use this to rebuild the desktop. You can optionally save the desktop files, or even restore previously saved files if you like. No matter what, rebuilding the desktop cannot hurt, and should be done once a month.

Preferences are the files that store all of your custom settings for your programs. When these files become corrupted, all sorts of strange things can happen. By throwing the preference file into the trash, and restarting the application, you can quickly see if that was the problem. If so, you will need to reset all of your setting, but if it's not, replace the old preference file so you don't have to go through that (sometimes very long) process.
   Bonus Tip: One of the most common error messages these days is a Type 2 error. This error means that a program is trying to execute an instruction that the computer doesn't understand. This can be quite frustrating, because you feel like you have no control over it. Well, I have found that deleting the preference files for the program in which this is happening cures the Type 2 errors about 75% of the time. That's definitely worth a shot.

Apples Disk First Aid, which ships with every Macintosh computer, can solve many hard disk related errors you are having. With this simple to use utility, you can check all sorts of stuff for degradation. Although Disk First Aid cannot repair every problem it finds, it's a good, free way to check out your hard disk. Remember, a healthy hard disk is a healthy Mac.

Utilities such as Norton Utilities and TechTool Pro can diagnose and repair a myriad of problems that Disk First Aid couldn't even dream of touching. They can also preform such actions as optimizing, recovering lost files, and more. If Disk First Aid cannot do the trick, try one of these utilities. They will repair nearly any problem you can have with your hard drive.

Once again, we come to that wonderful little utility, TechTool. This time, instead of rebuilding the desktop file, we will use the analyze button to check out the System on Finder files. This check has saved me many a times, and has found problems when no other utility could. If it does find a problem, you will need to reinstall your system software. After your reinstallation, you will have clean new System and Finder files. At this time, you should make a copy of those files to a backup medium, so that you don't have to go through the reinstall process if this ever happens again.

If TechTool doesn't find anything wrong with those files, there may still be something wrong. Open up the System Suitcase with a program called ResEdit (Warning: Using ResEdit can cause serious problems if used incorrectly. Be very careful if you must use ResEdit). When you open the system suitcase, it will automatically verify the resource fork of that file. If it finds a problem, you will have to go through that reinstall process, just like the step above.

PRAM, a small portion of volatile RAM, whose contents are kept by a small battery. The Parameter Random Access Memory holds information such as StartUp disk selection, Date and Time, monitor resolution and depth, alert sound information, and much more. If the PRAM gets corrupted, many strange happenings can occur. Ports may not work, the date and time may reset on every restart, sounds may not work correctly, and a whole lot more. By using TechTool once more, we can fully clean out the PRAM, with the safety net of a back-up, just in case. After cleaning the PRAM, often called Zapping the PRAM, you will have to check all your control panels, to reset all of your custom settings. This may be a pain, but it's more of a pain if you don't do it.
   Bonus Tip: If your PRAM battery ever goes completely dead, you will not be able to start up your Mac. When you hit the power button, the startup chime will sound, but nothing else will happen. When this occurs, you will have to go to your local electronics store, and pick up a new battery. Check EveryMac.com to see what kind of battery you need.

Alsoft's DiskWarrior is one of the newest utilities to come about. This one hit wonder doesn't do much, but what it does do, it does it well. DiskWarrior will take a look at your directories, and rebuild entirely new ones from scratch. This is much better than Norton Utilities' or TechTool Pro's patch approach. By rebuilding the entire directories, everything will be fresh, and work better than new. And since the directories are involved with everything you do on your Mac, you can see how important this program can be.

Sometimes, peripherals can cause problems that you would never think of. By unplugging all but the mouse and keyboard (and sometimes even those), you can quickly tell if your peripherals are causing problems. If so, reconnect them one at a time to find out exactly which one it is. Once you find the culprit, contact the company for a replacement, or for an update version of it's drivers.
   Caution: Older Macs (pre Summer 1998, Beige G3's and earlier), have ports such as ADB, SCSI, and Serial. These ports are NOT hotpluggable, which means you will have to shut down your Mac before unplugging and connecting devices. Failure to do so can fry those ports, or even your entire motherboard! The newer Macs use ports such as USB and FireWire, which are hotpluggable, and can be connected, and unplugged while the computer is running without fear of damage. Keep this in mind when using this particular tip.
   Bonus Tip:Recently, I have been having a run in with Type 13 errors. These errors come about when a peripheral calls for attention, but the instructions to execute what it wants to do, are not in the RAM. By doing the procedure above, you can find out exactly what device is causing these errors.

Sometimes, RAM chips can corrode, or become corrupt. This can cause the weirdest errors you have ever come across. Unfortunately, the only way to check this is by opening your machine, and pulling RAM chips until you find the culprit. This can become long and very tedious as some machines require a complete disassembly and reassembly for every chips. If you do find a bad chip, look up the warranty from the place you bought it from, or the company that made it. Usually, they will simply replace the chip for free, and you can be on your way.

If you get to this step, you really had problems. Nobody ever wants to go through this process, as it can be the most time consuming, and most detrimental. With that in mind, the first thing you should do is back up your entire hard disk. ZIP, CD-RW, Tape backup, DVD-RAM, and Magneto Optical are among the leading media to use for this procedure. You will have to find the one that is right for you. To back up your hard disk, you can either copy everything to a bunch of disks, or get a program such as Retrospect to make the process much simpler. Just make sure you get everything, just in case something goes wrong.
   After everything is safely backed up, you will need to start up from your system CD. This is most commonly done by inserting the CD, and holding the c key during startup. Once you have started up from that disk, use Apple's Drive Setup to reinitialize the drive (Warning: reinitializing the Hard drive will erase everything. Use extreme caution when preforming this activity.). Once this is done, you will have a clean slate.
   Once your hard drive is empty, you can start the reinstallation process. First, reinstall the System from the CD. Next, you have two options. One, you can take many hours, and sometimes days to reinstall every piece of software form it's original disks. While this will get you the cleanest system, the time required is tremendous, and may not be worth it. That where your back-up really comes in handy. You can use the backup to restore all your programs, preferences, and the like to the way you want, with minimal effort. Either way you choose, you will have a brand new system, without problems.

The Power Management Unit controls various I/O aspects of Apple laptops. If the PMU is corrupt, a wide variety of problems can occur. To reset the PMU, follow the directions on the Apple Knowledge Base.

Similar to the PMU for laptops, desktops Macs have a microcontroller that handles many I/O functions. Again, if this becomes corrupt, strange happenings can occur. To reset the CUDA switch, you will have to open your Mac, and look around on the motherboard for a white button (many times it is near the RAM slots). Press this button once (only once) to reset the CUDA.

• Shift=Extensions off
• Space Bar=Open entension manager
• Mouse Button=Eject disk(s)
• 'c' Key=Start up from CD ROM
• Command+Option=Rebuild Desktop
• Command+Option+p+r=ZAP PRAM
• Command+Option+Shift+Delete=Startup from something other than main hard drive
• Option=Close all windows
• Command=Disable virtual memory

• Conflict Cathcer
• Norton Utilities
• TechTool Pro
• Download ResEdit
• Download TechTool