3. Number of Installed Programs
Each new program that you install/load increases the potential for generating quirky compatibility issues. Perhaps a program loads a dynamic library file (DLL) that conflicts with another one that is already resident on your system. The reasons for these potential conflicts are varied and numerous.
You can help alleviate this problem by dual- or multi-booting different installations of your operating system(s). For example, I currently multi-boot my system with the following configuration:
It's fairly easy to configure a Windows multi-boot. Everything required to configure the boot-selection is done automatically for you. During startup, you will be presented with a screen that gives you the option to select the operating system you want to use.
If you make no selection within 30 seconds, your system will automatically boot to the default operating system, which will be the last one you installed. You can change both the 30-second wait (I use 6 seconds), and the default operating system (the one I use most frequently).
In this way, you'll be able to install only the programs you actually need to each operating system. For example, I don't install any games to the O/S that's dedicated for editing digital video. Nor do we install any programs, except those directly related to the editing process. This improves system stability while editing video.
You can easily install as many copies of Windows 2000 as you want. But I have not found a way to install/use more than one copy of Windows ME/98 .. not that you would ever need to use more than one copy. But if you edit video, or something specific like that, installing two/multiple copies of Windows 2000 is something that can help maximize system stability.
The worst compatibility issues come from software programs that try to 'take over' particular functions of your PC. For example, both Winamp and Sonique are MP3 players. Both programs want to play your MP3s. Having one or the other installed is less likely to generate a quirky compatibility issue than having *both* installed.
When two different programs service the same file(s), they sometimes battle for the right to play/execute those files. Again it *shouldn't* matter .. there shouldn't be a problem .. but things don't always work the way they should.
4. Component Quality
If you only use your PC for basic things, you can easily get by with bargain-basement components. But, if you use your system as a workstation, you'll want to spend a little extra cash and purchase quality components. Specifically, I'm talking about:
Power supplies are relativity cheap anyway, so spending a little extra for a a good unit, that provides nice, clean, stable power, shouldn't be a problem. It can be difficult to troubleshoot problems related to the PSU. You want a quality unit that provides your system with plenty of power to spare. I use a 430-watt Enermax unit ( I have 6 hard drives, 3 SCSI and 3 IDE). Do I need 430-watts? No. Is my system rock solid? Yes. Any more questions?
The same goes for RAM. Generic RAM is fine for grandma's solitaire system. But RAM problems are difficult to troubleshoot. (You usually have to swap modules with a friend.) Pay a little extra and get the good stuff. The difference isn't much. I like Samsung and Mushkin. The best right now is supposedly Corsair XMS. You'll have plenty of other things to give you problems.
5. System Cooling
Here in Southern California, as in other parts of the country, heat-related stability problems can become an issue .. especially during the hot, summer months. Electronics, especially silicon chips, do not like heat.
During a particularly long hot spell last summer, I even considered purchasing one of those mini beer-fridges, and modifying the case to pump cold air into the case. Fortunately the hot spell broke before I had to get freaky.
You generally want one or two fans sucking cool air into your case from the front/bottom, and another fan (or two) exhausting warm air from the top/back, not including the PSU fan.
A larger case can provide a possible solution. If you cram lot of hard drives and PCI cards into small case, the heat will have less room to escape. A large case with plenty of cooling fans for adequate ventilation is a good solution for heat-related stability problems. You can sometimes tell if you're experiencing heat-related stability problems by removing the covwer and using a big room fan to blow directly on the motherboard. If the problems go away, heat is the culprit.
Unfortunately, more fans generate louder systems. So it's often a balancing act between noise & ventilation/cooling/stability. I heard that Panaflo makes the quietest fans. Some fans allow you to turn them up/on when needed, and down/off when not.
6. Established Products
Less-popular hardware & software has a greater chance of generating quirky compatibility issues. The theory is that less-popular products are used in fewer, total systems, which means that there's less chance that the product in question was tested in a system with your particular configuration.
There are literally millions of possible system configurations. Consider, for example, the endless possible combinations of motherboards, BIOS versions, chipsets, CPUs, CPU steppings, graphics cards, graphics card drivers, sound cards, network cards, modems, operating systems, patch versions... ad infinitum.
Sticking with established, popular hardware & software means that
it's more likely that someone out there has a system configuration similar
to yours .. and that the product manufacturer has already worked out
the bugs associated with that (your) unique/particular configuration.
Yet this is not a hard-and-fast rule. Some obscure components and programs are well-designed and well-coded, and come with considerable testing. While there are also widely used products that are poorly designed and problematic.
In general, sound cards and video-editing cards tend to be two of the more problematic PCI add-on cards.
7. Program & Driver Updates
In general, the initial release (v1.0) of anything is the *most* problematic. Companies are often under (financial) pressure to release a product .. so they can begin generating revenue as soon as possible. Too often (not always), products are released before they're ready for 'prime time'.
In general, the smaller updates are safest. For example, an update from version 1.5.6 to v1.5.7 is much safer (less likely to generate problems) than an upgrade from v1.5.7 to v2.0.
This is cuz manufacturers typically add new features to the bigger upgrades, whereas they simply fix bugs in the smaller ones. Your particular system is more likely to experience quirky compatibility issues with new features .. than it is with simple bug fixes.
This is not a hard-and-fast rule. There will be many vX.0 updates that you'll have no problems with. But, on average, these tend to be more problematic.
In general, it's safe to install the smaller upgrades. But you should ask around before installing the bigger updates .. to see if others are experiencing any problems. Ideally, you want to ask someone with a system configuration similar to yours. That report will be the most meaningful. Find yourself a few good forums frequented by people you like. This is where you will post your questions.
You'll find that some updates cannot be uninstalled .. such as Microsoft's
drivers. This is why it's a good reason to use an imaging utility
such as Norton
Ghost to create back-ups of your system that you can use to 'undo',
so to speak, any problems. Ghost has saved my hide more times than I
can to recall.
8. Electrical Power
Depending where you live, the quality of electrical power supplied to your PC will vary. It's hard to tell whether or not you have 'clean' power, cuz you can't see electricity. If you're not an electrician, you probably don't know how to measure it. Summer is generally the worst time of year, cuz that's when people run their air-conditioners, which consume a lot of electrical power.
Power surges and 'dirty' power have a negative effect on sensitive system components. High-quality power supply units smooth out these surges and fluctuations better than poorly manufactured ones.
Here in California, it's the worst. For this reason, you may want to consider purchasing a UPS, which stands for Uninterruptable Power Supply. A UPS is basically a box that contains a battery for back-up power, which kicks in whenever your system loses power, or the supplied power falls below a minimum acceptable value (voltage).
I heard that APC makes the best UPS. I have the Back-UPS 650. It works well, making a chirping sound whenever incoming power falls below the minimum acceptable. I've had it for a few years and never had to replace the battery yet (~$35). Ars has a review of the unit post here. The 'Pro' version costs more cuz it comes with automatic shutdown software that you will probably never use. Buy.com sells the 650 for ~US$230. Beware of shipping costs cuz these things are heavy (the battery).