Ports and Connections:
There a lot of different gizmos and gadgets that can be hooked up to a personal computer so you'd better make sure that your new system has all of the required connectors so you can buy them all. I really don't think you should buy all the gizmos and gadgets, but at least you should have the option.

The most important ports that you absolutely have to have are as follows: Mouse, Keyboard, Power, Printer Port, Serial Port, USB.

Some of the ports that it would be nice to have but not absolutely necessary include the following: SCSI, Ethernet, IEEE1394 (otherwise known as FireWire or iLink), and PCMIA. Of course none of those ports are essential to the smooth operation of your desktop computer but if you plan on purchasing a specific peripheral that uses one of these ports then you should get a system with the appropriate port.

Warranty/Support:
When you decide to buy a computer system you will end up having to make a choice between a large manufacturer or a locally built system. Often the only difference that is readily evident to the consumer (besides price) is the difference in support/warranty offered by the big guys as opposed to the little guys. Of course, how important warranty/support is to you can be directly connected to your level of computing expertise. If you know a fair deal about how to operate a computer system and the perils involved with doing so you might not be so concerned about whether or not a 24 hour Phone Line is available. On the other hand if your system is a vital part of your business operations then an excellent warranty/support service plan might be much more important to you. 

So depending on your computing needs the importance of high quality warranty/support can vary greatly among different users. This could make your decision between purchasing a major brand name as opposed to a locally built model a lot easier.

Software Bundle:
Something that can be a very important consideration when purchasing a desktop system is the software bundle packaged with the computer system. This level of importance can vary depending on your needs as a computer user. If you are purchasing a second or third system then chances are you already own much of the software you intend on using, if this is your first system that it is a good bet that you have little or no software and would appreciate an extensive software bundle. 

All new computers should come with a full version of the Operating System you intend on using in your computing activities. The next most important piece of software is some kind of application suite. These suites usually contain such applications as a word processor, spreadsheet program, time organization tools, and Internet productivity software. Be reasonable in your desire for software, if your building a system for your kids then there is no reason to demand that Office 2000 Professional be included, as Microsoft Works will work just fine. Remember the software included with your system should correspond to your actually computing needs.