Fixing unexpected problems when upgrading a PC can weigh heavily on the true, total cost. However, the money you spend on a modest upgrade may still be substantially less than what you would spend for a brand-new PC. Sometimes it's a matter of time: The more valuable your time is, the chances are you'll buy new.
Before you upgrade or buy new, ask yourself these questions:
How old is the system that's under upgrade consideration?
If it's more than two years old, an upgrade is already iffy. If it's more than three years old, don't bother -- buy new instead.
What's the wattage rating on the power supply?
Most upgrades depend on reusing the case, which in turn means reusing the power supply. If that power supply isn't rated at least 240 watts, it's probably not worth recycling; in fact, it's better if it's rated at 300 watts or better. A sure bet is 400 watts or better, if not too noisy.
How much memory is in the PC?
The cheapest, fastest and easiest upgrade for any PC is more RAM. Though older RAM can cost more than newer RAM with the same capacity, adding another DIMM or two is no big thing. Many Windows users report significant speed increases after adding more RAM, especially those who work mostly with personal productivity applications (like Microsoft Office, e-mail and Web browsers). I doubled up the RAM in a five-year-old Dell Inspiron 3800 in January 2005 and eliminated most system slowdowns completely.
How big are the disk drives?
Even a two- or three-year-old machine may have no drive with more than 40 GB of disk space, perhaps even less. It's easy, and inexpensive (less than $100 for a reasonably speedy 7200 RPM ATA-133 drive of 160 GB or bigger) to replace older, smaller drives. The potential "gotcha" here lies in making sure your motherboard or disk controller can handle the big, moderately fast drives available so cheaply today. (Tip: Check your motherboard manufacturer's Web site.)
How much did the original system cost?
If you bought something purely on price, it may not be worth upgrading when you consider the ferocious pace of PC technology advancement. However, a desktop system that cost more than $1,500 two or three years ago may include enough quality components to be worth recycling through an upgrade. (Tip: if a new motherboard, CPU, memory and drives will cost you more than $500 it may not be worth it; if they'll cost you more than $700 it's definitely not worth it.)
How do you use the target system?
If the PCs serve purely as a platform for simple productivity apps, modest upgrades (like memory, drives or motherboard and CPU) may make sense. If a PC is used for more demanding work such as CAD/CAM, graphic design or heavy-duty number-crunching for example, buying a new high-end system will probably provide better results than upgrading.
What's your overall budget?
If you can't afford more than $400 or so, modest upgrades are basically your only option. If you can spend more than $1,000, buying new will mean less work and time invested and may produce better results. If you're in the gray area from $400 to $1,000, do your homework and weigh the costs of upgrade parts against the cost of a similarly equipped new PC. Don't forget that many retailers and system vendors offer trade-ins for old equipment, and you may be able to use your old system to take some of the sting out of paying for the new one.
It's as easy to throw away good money on an upgrade as it is to waste money unnecessarily on a new PC that offers more performance, storage or special features than you need. The secret to success lies in understanding how the costs involved can deliver a payback of some kind: If the payback over a year or two (at which time you'll face the buy versus upgrade issue again) matches the costs, it's barely worth doing. If it exceeds them, it's an increasingly smart business decision. If it fails even to meet the projected costs, don't do it!
Ed Tittel is a full-time freelance writer, trainer and consultant who specializes in information security, markup languages and networking technologies. He's a regular contributor to numerous TechTarget Web sites, technology editor for Certification Magazine, and crafts twice-monthly Web content for CramSession called "Must Know News." He's also the author of a Wiley book released in December 2004 entitled The PC Magazine Guide to Fighting Spyware, Viruses, and Malware (ISBN: 0764577697).