I recently purchased a computer at Best Buy, which advertised in-store for a free RAM upgrade from 356 megabytes to 512 megabytes. How might I tweak the computer to reveal how much RAM it actually has?

There are two ways to read the actual random access memory offered by the chips plugged into the sockets on any given PC. The easiest is to right-click on the My Computer icon and select Properties in the drop-down menu. There you will see a report showing both the amount of memory on board and something to identify the microprocessor on your machine, such as Pentium II or Pentium III or such. Yours should say 512 or thereabouts for RAM.

If you don't trust this sign, you can also use the DOS part of the operating system to read memory a little closer to the machine's internal software.

Click on the Start button and then Run. Type the word command in the Run box. This will bring up the DOS command window. There you can type mem/c at the command line prompt. Hit Return and get a readout of RAM as well as how the machine has earmarked RAM for use while running the operating system and the programs you have.

Jim Coates writes for the Chicago Tribune, a Tribune Publishing newspaper. Send e-mail to jcoates@tribune.com.