I don't know the manufacturer of the computer, but I know that Dell uses shoddy RAM in their machines. For instance, my parents have an Intel Pentium IV with 800 FSB with PC2700 RAM. This is a marketing ploy by Dell because they can advertise that the computer has 512 MB of RAM, and the average consumer thinks "Wow, 512 RAM is great". They don't think to check RAM speeds.
Since his computer is pre-built and uses PC2700 RAM with an 800 FSB processor, I wouldn't recommend overclocking the memory. If the manufacturer put in PC2700 memory in the first place, chances are it is not very high quality and would be EXTREMELY unstable if overclocked.
Jesus said to him, "I am the way, the truth, and the life; no one comes to the Father but through me". -John 14:6