Buying a computer

Please note that these guides do not constitute legal advice and any information provided in the guides should not be construed as legal advice or legal interpretation. We do not accept any liability for any loss caused by your reliance on this guide.

The DoneDeal guide to buying a computer

Price check

  • Ask the seller the age of the computer you are buying. Check its initial retail price.
  • Computers devalue quickly. They are said to lose 2% of their value every week. Do the maths.
  • New technology is upgraded and rolled out by manufacturers constantly.

Basic functions

  • Before buying, ask the seller to turn on the machine and give you a tour of its capabilities.
  • If the machine is in good working order, most sellers will be happy to show you how it works.


  • When buying a computer, always enquire about its memory capacity.
  • Memory equals efficiency. Good memory helps you quickly access the information or programmes you frequently use.
  • Office programmes or multimedia editing packages are memory-hungry. 2GB of RAM is the minimum a machine should have for these jobs.
  • Gaming machines need between 2GB and 8GB of RAM.
  • You can check all of these thing on the computer itself.


  • The processor is your computer’s brain. Higher-spec processors speed up your machine.
  • The main processor manufacturers are Intel (Celeron, Pentium and Core processors) and Advanced Micro Devices (AMD) (Sempron, Athlon and Phenom).
  • For gaming, Nvidia is known for its GeForce processors. Processor speeds are measured in GHz.


  • If you need your new machine for work purposes, to write your epic novel, or to keep track of accounts, you will need at least some basic software.
  • You’ll need Windows for a PC or iOS for a Mac. These are often bought separately.

Examine everything

  • Check carefully for any physical damage, and ensure everything promised in the DoneDeal ad is in place.
  • Check that USB ports are working. These are needed to facilitate external hardware like dongles.
  • Check for a CD/DVD drive. Is it working?
  • Check the screen for dead pixels, haze or discoloration


  • If you have a HDTV it will have a digital port labelled HDMI/DVI. This allows you to connect your machine to the TV via the HDMI port. That’s handy for streaming movies.
  • Check if the computer has a HDMI port.
  • To connect, you will require a HDMI connector cable. Ask the seller if there is one. Connect by plugging the cable into the correct ports.


  • Check if your purchase comes with an integrated webcam.
  • If not, ask if there is a regular webcam included with the deal.
  • If there is, make sure it works. Turn it on. Try it out. Pay attention to image quality.

Screen size

  • Desktop monitors come in a variety of sizes including 15”, 17”, 19” and 21”.
  • If using a computer for more than two hours a day opt for a 17” at least.
  • Larger screens benefit graphic-intensive projects, but 15” screens are more portable and are fine for word processing or email.
  • Think about what you want before you buy. What will you use it for?

Screen resolution

  • The very minimum resolution on a screen should be 800 x 600.
  • Bigger resolutions make for sharper graphics.
  • Some computers will not support higher screen resolutions.
  • In Windows, set the screen resolution by clicking on ‘properties’, then ‘display’ and ‘settings’.


  • Tablets, iPads, consoles and some computers have touchscreen electronic visual displays which are navigated with a finger or a stylus.
  • Check that the touchscreen is calibrated. Does it react accurately when touched?
  • Examine for scratches, damage or any greasy marks on the screen.
  • Ask if it has a protective case. Touchscreens damage easily.


  • Take your time when checking the battery: If the computer is being sold as having a workable battery, unplug it and let it run on the battery’s power for at least 20 minutes. If it cuts out, you’ll have to replace that battery.

Things to consider

  • You may want to connect to the internet via WiFi or use Bluetooth to share files.
  • Go through the start-up menu to see if your purchase is equipped for this.
  • If music is your first love, you may need to upgrade the soundcard. Standard soundcards are not made with musicians in mind.
  • If gaming gets you giddy, you may need to upgrade the standard video card later for higher definition graphics.


  • Ask the seller if there is still a manufacturer’s warranty in place on the second-hand machine they are selling you.
  • Ask for proof of purchase in case you need to invoke the warranty.


  • You may like to upgrade or add software, buy extra components or add hardware like a printer.
  • Ask for items you may require on DoneDeal’s ‘wanted’ ads section.
  • Use your new machine to search on DoneDeal. Set up an email alert for items you may want.

Be smart, deal smart

  • Take all the usual precautions when buying a computer.
  • Examine the goods carefully.
  • Don’t bring home a dud.