I bought 2 of those 1GB pieces of RAM (Kingston ValueRAM 1GB 533Mhz DDR2 Non-ECC CL4 240 Pin DIMM)for my Dell Dimension desktop computer to top up the 2x512 MB RAM I had purchased it with. I added the new RAM to slots 3 and 4 which were free, I had RAM in slots 1 and 2 already, so I left it there. I am not a specialist at all, so I thought I migh get things wrong, however everything went smoothly and when I reconnected the computer and switched it on, the new RAM was automatically recognised. A total of 2.99GB now. The computer runs faster, though this is mostly noticeable in memory-intensive graphical applications and not that much in everyday tasks. I have used the product for 2 weeks now and am happy with it.