Many consumers who purchase a computer often do so without fully asking themselves, "What do I need this computer for?" The end result is a computer that either doesn't perform well on the tasks you purchased it to do, or a powerful computer that cost a lot and yet its capabilities are hardly ever used to their full potential.
What Specific Tasks Will Your Computer Perform?
The reason you buy a computer make a lot of difference regarding what hardware configuration you should look for and the price you have to pay for it. Knowing the specific tasks you will perform on your computer ahead of time will help you get the parts you need while avoiding paying for those you don't.
You also want to buy a computer that lasts. If you buy a computer that is already outdated, you might run the risk that you are not able to run the latest software on it.
What Technical Support Options Do You Have?
With most new computers, if they were set up right and run okay for the first 2 or 3 months, then they will probably be okay for years (unless you do something wrong to it yourself). However, you want to always provide yourself with some form of support or warranty to fall back on.
Where Will You Locate Your Computer?
When placing your computer, you should be aware of how a computer's cooling system operates. A fan at the front or sides of the computer case pulls air inside, then another fan (sometimes 2 or 3 fans) will drive cooler air directly onto the processor and out the back of your computer. Therefore, its important not to block the flow of airs near these fan intakes (basically, keep a lot of clear space around your computer).
A computer also needs to be located away from electrical appliances that could cause interference, in a room that is not humid, and away from direct sunlight. You will also want to keep it away from heating vents and basically anything that will cause it to get too hot or too dusty.

